To the tune of "Modern Major General" from Pirates of Penzance - the picture of a moden lj user, courtesy of the journal of tygher
[edit: cut and pasted with permission, because I forgot her journal is friends-only! *facepalm*]
I am the very model of an LJ personality.
I intersperse obscenity with tedious banality.
User-names I have plenty of; both genuine and ghosted, too,
On all the communities that my drivel is cross-posted to.
Your bandwidth I will fritter with my whining and my snivelling,
And you're the one who pays the bill, downloading all my drivelling.
My enemies are numerous, and no-one would be blaming you
For cracking my head open after I've been rudely flaming you.
I hate to lose an argument (by now I should be used to it).
I wouldn't know a valid point if I were introduced to it.
My learning is extensive but consists of mindless trivia,
Designed to fan my ego, which is larger than Bolivia.
The comments that I vomit forth, disguised as jest and drollery,
Are really just an exercise in unremitting trollery.
I say I'm frank and forthright, but that's merely lies and vanity,
The gibberings of one who's on the limits of his sanity.
If only I could get a life, as many people tell me to;
If only Mum could find a circus freak-show she could sell me to;
If I go off to Zanzibar to paint the local scenery;
If I lose all my fingers in a mishap with machinery;
If I survive to twenty, which is somewhat problematical;
If what I post were more mature, or slightly more grammatical;
If I could learn to spell a bit, and maybe even punctuate;
Would I still be the loathsome and objectionable punk you hate?
But while I have this tiresome urge to prance around and show my face,
It simply isn't safe for normal people here in cyberspace.
To stick me in "Old Sparky" and turn on the electricity
Would be a fitting punishment for my egocentricity.
I always have the last word; so, with uttermost finality,
That's all from me, the model of an LJ personality!
[Second edit: So far as I can tell, the most original version comes from a Mr. Tom Holt, and can be found here