Megazoomer makes windows full-screen. Just press Command-Enter, and the front-most window grows to fill your entire monitor. Press the same keys, and it shrinks again. Like Graffiti, you have to download SIMBL in order for it to work.
v0.5, released 19th September 2009- snow leopard and 64-bit support – Download (20 KB)
v0.4.1, released 16th July 2006- fixes window-switching bug in terminal; no more console warning messages – Download (89 KB, includes source)
v0.4, released 5th July 2006- more compatibility fixes; multi-monitor support; now a universal binary – Download (116 KB, includes source)
v0.3, released 8th April 2006- tons of compatibility fixes; now works with iApps and non-English localizations – Download (97 KB, includes source)
v0.2.1, released 24th March 2006- fixes window-closing bug – Download (84 KB, includes source)
v0.2, released 24th March 2006- now works with all apps, not just terminal – Download (86 KB, includes source)
v0.1, released 20th September 2005 – Download (86 KB, includes source)