I received my [u]MicFlex USB microphone[/u] from MacMice yesterday, and it’s pretty cool.

“The MicFlex is plug and play compatible with all USB equipped Macs with OS 9.1, 9.2 or OS X 10.1 or higher. It is also plug and play compatible with USB equipped Windows 98Se, Win2000, or Win XP machines.”
The base is smaller than it looks in the picture–3.5" across, but is quite heavy, so it has no trouble with the gooseneck being extended as far to the side as it will go. The mic is about 1.75" long and 0.75" in diameter.
It doesn’t have a separate power cord, and on my machine it requires too much power to plug into my keyboard (which is already plugged into my screen) so I have it plugged into one of the USB outlets on the computer, but I can still get it about a yard from the computer if I want to.
The mic is very directional. I’ve been experimenting with doing recordings using Audacity, and it doesn’t seem to pick up much in the way of noise from the computer fan (nothing I can hear, anyway), even though it’s sitting on the same formica-topped table, just a couple of feet away. The heavy base and the long, thin neck probably help there.
As far as I can judge, the sound quality is excellent. The gooseneck design is very convenient for getting the mic exactly where you want it for either whistle or guitar.
I don’t know whether it really is “the best USB microphone in the world”, as their Web site claims, but it’s mighty nice. If you need this kind of mic, the price seems reasonable to me.
When I get a little spare time, I plan to put up a page with scales played on all of my whistles (16 high D’s) and maybe do a little quiz to see how folks here are at matching sounds to makers.