Download and use a program called Android Central Sideload Wonder Machine. It's a one click solution, works amazingly on the Captivate and requires no hassle. The program claims to work on un-rooted phones (though mine is rooted).
My girlfriend's Captivate is not rooted though so I will test this out on her phone as well to confirm it. Check it out though. I've already gone to town with this and it works great.
The Android Central Sideload Wonder Machine - Android Forums
My girlfriend's Captivate is not rooted though so I will test this out on her phone as well to confirm it. Check it out though. I've already gone to town with this and it works great.
The Android Central Sideload Wonder Machine - Android Forums