For all you flatland tricksters out there here's a relatively easy one to do.
Step 1: Approch a standard sized curb with about 3-5mph of speed. The slower you go the harder it will be to start the endo process but the faster you go the more chances you're just going to flip over. Basically a few mellow pushes into the curb should be good.
Step 2 & 3: Once you make contact with the curb throw your weight forward enough to lift the back wheels off the ground.
Step 3 & 4: As your back end goes higher you will need to level off the endo and stall the board. The idea is to be close to vertical but not quite. At your farthest stall point go for the tail grab. Grab it. Smile and then let the rear end of the board go back to the ground. When you land try to keep some of this backward momentum in order to roll back out from the curb.
