aero glass open windows?

[chaseincats]

Im pretty sure this isnt a feature but was curious if it could/is addable via an outside program:

Was wondering if it was possible to have an open window permanently in transparent glass form (say you have multiple windows open and you hit/hold alt-tab the windows other than the highlighted one turn into those glass pains) until its moused over

a use for this could be an instant messenger buddy list

does anyone know if this is possible?

 

[Uber Philf]

Not sure, but id like to know how if it can be done.