What microphone to use in imic?

[Macmon]

Read some articles on imic and since I am planning to record audio for some presentations that will incorporated for home video, what particular microphone is needed to make the recording acceptable?
Read that a preamp mic is needed?

What particular local mics are acceptable?

Thanks

[lasbac]

Has anyone used the logitech usb desktop mic? Is it good? Is there any available locally? Are there other similar mics? I need an external mic for my powerbook.

[ultratramp]

I went out and bought the Samson CO1U usb mic discussed here and it performed way better than recording thru an imic. Im not sure if its quite pro-level, but its right up there, and i got the results i desired.

EDIT: sorry Macmon, my reply seems to have answered lasbac's querry better than yours. I used a Shure SM58(?) mic that I lined thru an imic via an extra converter to the minijack the imic required. Resulted in lackluster audio. Searched and found that the Samson was best value alternative.