I had about 30 gigs of free space. I installed lion and now (2 weeks after I installed) I only have 3. I have not downloaded or bought apps that use significant space .... I am using an imac ... Any ideas???
They are in /Volumes/MobileBackups, but as you said this should not be enabled on your iMac. If it is enabled, turn off then turn back on Time Machine and it will delete any local backups.
go to terminal and run "diskutil list" to show all volumes and their size/spce left.