Well i guess you can use it as I use my MorphOs machine..
Surf safely on the web - no spyware, virus etc.
Music/mp3 - Play your music
Videos - Play all your divx and video files, download videos from youtube etc...
Mail - Again, no virus on this one... Yam is so cool and fast, something else than outlook hehe...
Games/Emulation - play classics as you do now
games - like quake 1-3 and some small games...
Art/pictures - import from digital camera, repair and fix pictures
Other advantages is fast boot, when i come home from work i just boot my machine, some seconds later its ready (finishd booting, not like windows)... Also not so annoying and slow as windows...(8hours at work is enough every day)..
So many reasons, and its also fun
Just about everything needed, only problem is online banking wich doesnt work good..