There are always an abundance of modifications you can do to an Operating System especially Windows XP. Things like different shells (explorer.exe alternatives) etc. can make your experience feel much more unique and even help your OS last a little longer. These are especially welcoming for those that are into the eye-candy of an operating system but don’t want to upgrade to Windows Vista.
Check out this list of 40 Great Desktop Mods with plenty of screenshots. There is also CairoShell which is still in Alpha stage of development but has a lot of potential at this point.
Check It Out> 40 Great Desktop Mods
Cairo is total vaporware and possible donation fraud crap.