There's nothing quite like having a bunch of robots fight each other. Since that giant Gundam in Japan hasn't gone fully mobile yet (not to mention it doesn't really have anything to fight except maybe a horde of BigDogs), we have to settle for video games.
iPhone and iPod Touch owners can get their robot fighting fix via Vogster Entertainment's Robocalypse: Mobile Mayhem, which has just recently launched on the App Store.
Based on the DS RTS game Robocalypse, Mobile Mayhem has players building and commanding robot armies to fend off attacks from the evil yet very polite Demolisher and his near-endless supply of mechanical marauders
The game features 10 unit types, 20 varieties of weaponry, 17 campaign missions, 18 unique multiplayer maps, multiplayer support for up to four players, a cast of powerful Hero robots and an intuitive touch-screen interface. You can grab a copy for US 4.99.