Microwave/Double Boiler - Does it make a difference?

[sweet-lovah.livejournal.com]

I am planning on making lip gloss for my frineds for Christmas, but becasue I live in residence at school I don't have access to a stove (sounds pathetic, I know) ... or lots of money to invest in a double boiler. So my question is, does it make a difference if I use a microwave instead of a double boiler? This question also applies to M&P soaps, which I also plan on making (from a pre-made mix that I just plan to buy at Micheal's).