Also, if I understand it correctly a redstone current led into the stationary liquid block (might be enough leading it into one of the adjacent blocks, come to think about it.. Haven't tried that) can alter the state of stationary lava (also stationary water) to start the flow. Only works once though, but it's a nice tip if you're Op on a server and want to build non-auto-reversible trap or mechanic. Been a while since I tried it though so it might have been altered in recent updates.

If your using the /give only lava items I think they work the same pretty much.

Lava will flow when you place it, Stationary Lava will stay still until a block around it moves/is place/is taken away.