I prefer using snapnames myself, what I do is look at the whois for the name I am interested in, if it is registered by network solutions I have found snapnames usually get it.
I think different drop companies have arrangements with different registrars, I have'nt figured out who works with who yet ! (I may be wrong about this)
If I am really wanting the name bad I will backorder with snapnames & GoDaddy to increase my chances a little - the biggest thing that puts me off godaddy is that they put the domain up for auction real early, once you have Won ! your backorder sometimes you have to wait another 60 days before you can use it, if the previous owner wants to renew the domain within that time they can, you will then be given your money back - so don't get to excited when you win - not until you have full control of it anyhow :sold:
Snapnames is favourite at the moment until I learn any better. :]
Happy Hunting