I remember someone posting a list of some other back-ordering services besides snapnames and expirefish.. maybe search the posts. Ah, found it:
Thewitt posts some companies (about 10 of them) who offer similar services to snapnames. And I'll add Domainmart.com to the list.
On another note, I've had success just trying to pick up a few domains after
(normally the same day though) they expire, like when NSI has one of their drops of like 50,000+ in a day. I've picked up around 6 or 7 domains like this on my spare time, and sold 4 already
($850), well, it's nice for me, don't have a job yet. And I do understand most (I think) people who use SnapNames or similar services try andget the domains for their own use, not in the hopes of a sale.