AI have someone that wants a rainbow cake...standing up! In the picture like this one http://www.flickr.com/photos/courtneyscakes/3207232961/. I am lost on how to make it stand...Help!

I actually have a pan in that half-moon/semi-circle shape, but you can 1) bake a circle and cut it in half or 2)put a divider (like Batter Daddy Pan Separator ) in the pan so you get a half-moon shape. Attach dowels to (or THROUGH, which I prefer) your board and place the cake over them. Cut a fondant semi-circle to start the rainbow, then different length strips in rainbow colors to finish. Seems to me the bubbles are just fondant balls in varying sizes.

Also, would you ice two half cakes together and stand them up?

1) Drill holes the diameter of your dowels in your board and put the dowels to stand in the holes. My drill bit is EXACTLY the same diameter as my dowels, so it's a really nice tight fit. 

2) It depends on how thick you'd want your cake. Here, pans are a standard 3'', so I wouldn't do two.