Do folding@home, help people out. SETI... heck, even if we found a signal, so what? It won't be going anywhere unless the civilization disappears, and by the time we get it, and they get our reply... well, we could both be gone by then. Or at least have figured out sub-space / multi-dimensional portals / hyperspace / warp theory / what-have-you (if we don't figure this out, honestly, then it's a waiting game. You can exchange signals, but the lag makes it have rather questionable benefits. Currently, any signals we broadcast basically just say "we are intelligent, and we are here", right?)