Works great!
I dont use Sprint myself, but a friend was looking for this functionality. After dabbling a bit with the app I found that it works as suggested. I love the fact that its real lite and works on virtually any phone as for as I can tell.
Not to steal your limelight or anything, but I can guess that this app might not be what some are looking for, so heres one suggestion.
Anyone who is not on Sprint ( or is but wants other functionality ) but wants a good locater app for their androids; check out Mobile Defense. I have been using it for my G1 on AT&T. They just closed the beta from the public, but should be releasing something official soon. It can locate multiple phones ( you will have to install an app ) , remotely wipe the data, send messages to, among others.
Lost my phone a few times and through the app I was able to pinpoint it within a few feet ^^.
Not sure if they will be charging in the future ( probably would be my best guess >.> ) but I plan on sticking with it for my AT&T phones.