"(I can't deal anymore with people listing other people's identities as Do Not Wants; it's rude and it's painful to match.)"

Yeesh! Rude, indeed.

That HL template looks quite sensible, if we do an exchange. So does the idea of posting sign-ups publicly. (Quite a number of exchanges do that, though not for actual claiming purposes.) Or, if we play challenge-style, multiple prompts for people to pick from.

I'm pretty easy on all the options. Um ... not so keen on bingo, I guess. Not sure how it would work, for one thing.