i badly need mic for skype. i wanna buy a usb sound card.

my question is mac is plug and play supported right.so if i buy a cheap usb sound card will it work
is there any possibility that it will work. any success ? i know it's hard to tell. But give me advice.
is there any chipset i have to check..?
or i have to choose only creative product...?

suggestion needed.

Thanks
demigod

---

MAC OS x : Yet to figure out version.
CPU:AMD E-350D APU MOBO:GA-E350N RAM: 4GB 1333Mhz GPU: AMD Radeon HD 6310
HDD:Seagate 160GB SATA DVD-RW: Transcend USB Burner USB Mouse & Keyboard
WebCam: Logitech C910

Chipset:
AMD Radeon HD 6310
North Bridge: AMD A45 FCH