you should give your files to peers (and in return store their files) so that if a catastrophe strikes your area, you can recover data from surviving peers.
a compiler cache. It acts as a caching pre-processor to C/C++ compilers. Caching previous compilations and detecting when the same compilation is being done again. (needs GCC or similar)
a Direct Connect clone, a windoz client allowing users to share their files and talk (like IRC but more software sharing oriented) using a proprietary protocol.