I hate domain snatching. I remember last year, I was on namecheap searching to see if some domains were registered. Well they were available one minute and the next few minutes they were gone. I have learned since then to just use my browser to see if the domain is available. But today I tried to register a domain, but it failed and now someone else has taken it.
Unfortunately looking up a domain name on your browser won't prevent them from seeing what's being looked up. If you really insist on being able to lookup domain availability with little risks of it being taken, then I suggest you use the Registry since all registrars check that out first without sharing results with othe registrars: http://registrar.verisign-grs.com/whois (for .com)
Well well well.. the very same domain which dropped and I lost it coz someone else had registered, is now available. Just goes to show the domain tasting racket that these domain registrars are running. I'm glad I just checked out of the blue. I lost the domain around 15th dec 2006 and now I have registered it again. Yipee!! Lesson to be learnt: Dont lose hope if you lost it. Just try it out after a month and not frequently.