On the message boards, I think variants are fabulous. I love learning the ways other people say things and it adds a lot of colo(u)r and flavo(u)r to the posts. Nitpicking someone's spelling on a message board is pretty obnoxious.
In fanfic, I can skim past "centre" or "colour" but some others are more jarring. Once, someone wrote about Lois's jeep pulling away from the "kerb" and that pulled me right out of the story. The meaning's obvious and I *think* that's the correct Brit spelling, but it was different enough to stick out.
As for accepting misspellings or txtspeak in college papers...
Rage, rage against the dying of the light...
PJ
