MetaGeek has recently updated the Wi-Spy software to Chanalyzer 2.1.6. They also have other softwares for the Mac updated. Oh, and I see Wi-Spy now has a 2.4 product which has an external antenna and has ballooned in price to $400. Ouch! Still, the original is available and the software works with both.
I’m not sure the external antenna is worth the price, and at $400, they’re really moving out of consumer-land geekery and into a more small office wireless support market. Unless I consult with wireless analysis and site surveys, I don’t think any home user will lay down that much money for this tool.