Has anyone tried using NetSol's back-order feature? You pay $50 and they watch for a domain name to be released and try to get it for you. The fee covers the registration for a year if you can get it but you pay whether you get it or not.

Any other services like this?

expirefish.com & namewinner.com :D

DomainMart also offers a service very similar to SnapNames

http://www.domainmart.com/DomainNames/agent/expired.htm

It's $10 cheaper than snapnames (netsol's backorder feature) and basically does the exact same thing, but IMHO I think with snapnames you'd have a better chance on grabbing the domain, since DomainMart also offers tons of other domain related services.