Buying an external microphone for gaming?

What would be the best microphone (either standing desktop or clip-on) to plug into a laptop for use in gaming? I want to ditch my Logitech USB headset because it's not very comfortable and the only things that I listen to on them are the voices of my mates on Ventrilo or TeamSpeak.

The other thing is that I've got a set of Sennheiser HD215 headphones that I want to use when I'm gaming and/or when I don't want to make an absolute racket with my 5.1 stereo...but of course the Sennheisers don't have a microphone to talk through Ventrilo.

So the obvious question is: what would be my best option? I've heard a lot about this Zalman microphone but when you add shipping to it, it comes up to around the same price as a Sony or Audio-Technica clip-on mic (I live in Australia, hence why the shipping is so expensive). The popular choice from what I've seen is the Logitech desktop noise-cancelling mic but from what I've also read, it doesn't cancel background noise very well either and there's not very much space on my desk as it is for a microphone. However, it's cheaper by about $15.