You can try to install Yahoo! with wine but there are many bugs involved aparently...I've tried to install that way and I get the program installed but it will not work.

According to the wine website you can get 7.0 installed but it doesn't explain how anyone has managed this...

Anyway I'm going to keep at it and if I find out that I can get it working then I'll let you guys know.

oh and here is the link for wine that I found the information on