Simple product and hopefully of temporary use, but really nice because Spaces would be too frustrating to use without this correction.
Again the main reason is that I like to open a new window of a very common application (Safari, Terminal, TextEdit, etc.) on a given desktop, without it being sticky and in all possible situations.
Helas 3Spaces, does not orrect all Spaces lacks; it does bring all the functionnality we were used with other desktops applications before 10.5, and I cannot get one to work now (MacBook Pro intel leopard).