I can't install *.exe files or *.sit/*.sitx files...

I tried downloading a *.sitx file on my recently purchased eMac and it tells me there's no application to open the program. Apparently StuffIt isn't on OSX Tiger? So I try to download StuffIt, and it being a *.exe. file, I try installing it and get the same message about there not being a program to open it. So what am I doing wrong?

ok u download a PC version of stuff it
go bac to versiontracker and do a search it will give u the mac version

Doh...I feel like an idiot. Thanks. Still getting used to the whole switch from PC to Mac thing....

ahh dont worry man we all have moments like this..