What directory does Installous decompress .ipa files to when installing them on iPhone?

I ssh'd an .ipa file to the downloads section in Installous. When I tried to install the 1.2 gb file, I got an error saying I had run out of space as it tried to decompress the archive. Now I'm stuck with a full iPhone and I don't know where the partially decompressed file is stored so that I can delete it. Can anyone help? Thanks