Well, hello my first real post about wine!
Wine is a emulation layer for linux. Basically you can run various windows programs in linux.
To install wine in ubuntu, open the terminal
type: sudo apt-get install wine
and in fedora type : yum install wine
Now once you have it installed, keep the terminal open. Download the program you would like to run , from a website like download.com or for older apps , oldapps.com
Once downloaded make sure its in your home folder! Type wine /home/programnamehere.exe. Then you will see some random text from the program and if it gives you a weird error or doesnt open anything, probably means your program is incompatible.
Anyway, id like to show you me getting iTunes , yes itunes for windows or mac os x, working in ubuntu. Of course it runs really slow , but its a start. I downloaded it from oldapps.com, because the newest version doesnt work,you either have to download 7.0 or 7.2.
Heres the screenshot
http://www.flickr.com/photos/10763824@N03/2060020299/
Cool huh. All you have to download is run: wine itunes7setup.exe and the installer will start and then you can launch the application just like a normal one. Although it is nowhere near being native, its a start. Please Apple, give us linux users iTunes!