Ubuntu-compliant USB wi-fi device?

[Germano Rizzo]

Hi,
	I've got an Apple 12" Powerbook with Ubuntu PPC (happily) installed. 
The one and only thing I'm really missing in comparison to Mac OS X is 
wi-fi support, since there are no LinuxPPC drivers for my (infamous) 
AirPort extreme card. So, I'm willing to buy an USB device to provide 
wi-fi connectivity (I have no PCMCIA/Cardbus slots...), but I was 
wondering which models are supported by (Ubuntu) Linux. Can you please 
address me to something supported and with a discrete range of operativity?
	Thanks so much in advance,
		Germano