While Gravity is active, Pokemon can hit ungrounded targets (Flying-types, Levitate and Air Balloon users) with Ground-type attacks, despite their usual immunity. Sand Stream Gigalith can use this to support Sand Rush Excadrill, allowing it to fire off Earthquakes with minimal risk involved (usually with a Choice Band equipped to boost its power). Gigalith can also use Explosion to bring it in safely. Additionally, Gravity multiplies evasiveness by 3/5 (multiplies accuracy by 5/3), which makes Dracozolt another typical partner as it alleviates Hustle's downside. Here's a typical team using this strategy. It's essentially hyper offense. Keep in mind that it is very gimmicky, has obvious flaws, and should only really be used for fun though.