Mack.
Snapnames, enom, pool, namewinner, godaddy etc. all have domain backorder services. With most of these (not godaddy or snapnames) if more than 1 person wants the name you will be involved in an auction. Sometimes, the price can run up quickly - very quickly if the name is decent.
If your serious about getting a name, you should use as many of the above services as possible. Make sure you get snapnames, not because they are the best, but because they don't have an auction. Even with a snap you will want to use the big services to make sure you have a better chance of getting the name. Of course, there are independents out there (BD, ULT) that have their own powerful systems that could take the name out from under you.
Joe
My worry is that just by using some of these services, I might be alerting some domain sharks to the availability of the domain.
If the domain has a decent amount of traffic then they already know about it. If it is a great name with little traffic it could slide under the radar.
Or am I just being paranoid?
Not at all. Strange things happen, but you still have to play the game in order to land a decent domain...