As you no doubt know already, an anagram is a rearrangement of the letters of some starting text into another text that parallels the original, makes a commentary on it, or is related to it in some way. Most anagrams tend to be short (e.g., DORMITORY = DIRTY ROOM), but my main interest is in anagrams of medium to long texts (fifty or so to thousands of letters long). If you can't wait to get to the anagrams, just scroll down a bit; in the meanwhile, I thought it might be useful to discuss a few facets of the long-anagramming task.
The first, and possibly most important observation, is that writing a long anagram can be viewed as a form of constrained writing, that art form made popular by the Oulipo in which the writing of a piece is governed by certain somewhat artificial lexical or structural rules which, despite their seeming irrelevance to the task at hand, have a strong effect on the author's modes of expression and thus the end result. Oulipo members have written long texts without the vowel E, or only using the vowel E, or ones where every sentence starts with the same two words. In a long anagram, the constraint is simply to use a prespecified pile of letters (namely, those in the original text being anagrammed). The corners into which one is forced by the constraint often result in wild ideas or interesting turns of phrase that would probably never occur otherwise.
How hard is it to construct a long anagram? At first glance such productions seem quite astounding, but there are several tensions at work here. On the one hand, it surely take more effort to create a long anagram than it does to create a short one, simply because there are more letters to be put in their places. On the other hand, a larger letter pile provides more elbow room to manuever, thus making it easier on a per letter basis (except near the end, since forming those last few letters into words is just like making a short anagram). On the third hand, this additional freedom sometimes suggests extra constraints (beyond the basic anagram rule) to be imposed, such as poetical rhyme and/or meter, an acrostic, specific subject matter, etc. The result can be a set of multiple constraints that are very challenging.
Here are some favorite long and medium anagrams I've composed in the last few years. The long ones are each on separate pages; the medium-sized ones are just given right here.
Shakespeare sonnet #143
A sonnet-to-sonnet anagram, with meter and rhyme preserved, and an additional constraint as to the subject matter of the anagram sonnet.
Poem by Sylvia Plath
An example of an oft-used style of poetic anagramming, distinguished by three features: (1) the anagram closely follows the structure and flow of the original, (2) it does that while using a quite different vocabulary, and (3) the subject matter of the original is transmuted just enough to make the result fresh and interesting in some way.
Poem by Robert Pinsky
Similar treatment to a poem by the current U.S. poet laureate. The 'hook' is simple: move the setting to a different state of the U.S.
Let us now praise famous men (and women)
A famous text about the famous is turned into a list of the famous.
Which comes dangerously close to suggesting Samuel Johnson's remark about a dog walking on its hind legs. A poem in French that eschews the letter E is anagrammed into an approximate English translation of the poem.
This is a simultaneous anagram and translation. The English text is
both an anagram of and an approximate translation of the
first four tercets of Canto III of Dante's "Inferno",
from the original 13th-century Italian.
Original:"Per me si va ne la citta dolente Per me si va ne l'etterno dolore Per me si va tra la perduta gente. Giustizia mosse il mio alto fattore; Fecemi la divina podestate, La somma sapienza e 'l primo amore. Dinanzi a me non fuor cose create Se non etterne, e io etterno duro. LASCIATE OGNE SPERANZA, VOI CH'INTRATE." Queste parole di colore oscuro vid' io scritte al sommo d'una porta; per ch'io: "Maestro, il senso lor m'e duro." Anagram:"I am a portal to a sad place. I am a cover to eternal fire. Go, see our pit ooze craven memories. Elite persistence moved some creator; Divine omnipotence created me; I am solo orgies of primal love. Listen: ere me no denizens used our portal. I quit not, and I last eternal. FOREGO ALL HOPE, ALL MEN THAT ENTER." Crazed and curious, in a daze I sat To see man pour out over a portal; So I said: "Master, I cannot see its import."
It was a Dark and Stormy Night...
This is an anagram of the first sentence (whose first seven words, at least, are quite famous) of Edward Bulwer-Lytton's novel Paul Clifford. A hundred years or so after he wrote it, Charles Schultz appropriated those seven words as a running gag in his comic strip Peanuts.
It was a dark and stormy night; the rain fell in torrents, except at
occasional intervals, when it was checked by a violent gust of wind
which swept up the streets (for it is in London that our scene lies),
rattling along the housetops, and fiercely agitating the scanty flame
of the lamps that struggled against the darkness.
Tut-tut! Bulwer-Lytton's known penchant for inelegant, stagnant,
over-affected, cost-inflated prose evokes mirth a hundred years hence.
Ah-ha! A well-known comic strip talent hatches it - a textual gag for a dog:
(Snoopy wags his tail, sits at his typewriter, fidgets, and then
distills a classic theme: "It's raining, there's no light...")
A Doubly-True Anagram
This one anagrams 30 elements from the Periodic Table
of the Elements into 30 other elements (and all 60 elements
that appear in the anagram are distinct):
hydrogen + zirconium + tin + oxygen + rhenium + platinum +
tellurium + terbium + nobelium + chromium + iron + cobalt +
carbon + aluminum + ruthenium + silicon + ytterbium + hafnium +
sodium + selenium + cerium + manganese + osmium + uranium +
nickel + praseodymium + erbium + vanadium + thallium + plutonium =
nitrogen + zinc + rhodium + helium + argon + neptunium +
beryllium + bromine + lutetium + boron + calcium + thorium +
niobium + lanthanum + mercury + fluorine + bismuth + actinium +
silver + cesium + neodymium + magnesium + xenon + samarium +
scandium + europium + berkelium + palladium + antimony + thulium
But there's more: if we replace each element by its atomic number (position in the Periodic Table), there is still equality:
1 + 40 + 50 + 8 + 75 + 78 +
52 + 65 +102 + 24 + 26 + 27 +
6 + 13 + 44 + 14 + 70 + 72 +
11 + 34 + 58 + 25 + 76 + 92 +
28 + 59 + 68 + 23 + 81 + 94 =
7 + 30 + 45 + 2 + 18 + 93 +
4 + 35 + 71 + 5 + 20 + 90 +
41 + 57 + 80 + 9 + 83 + 89 +
47 + 55 + 60 + 12 + 54 + 62 +
21 + 63 + 97 + 46 + 51 + 69 = 1416
This is the longest doubly-true anagram ever constructed using the chemical elements - or any other set of this type, as far as I know.