IDK about making them adjustable yet, but with a single supply u could use an LM317 and the negative version the LM337, and just a few diodes, resistors, caps. It splits the input V, and balances ground in the middle between the 2. I made a little one add it worked good enough to run cheap op-amp oscillator circuits. So I guess it was fairly clean on the scope, I don't remember, but it was ok.
LM317/LM337 are good for (+/-) 2-37V and can handle 1.5A, and can be used in parallel, and can be made dual tracking adjustable, I've seen that in the datasheet I'm sure.
I bet there\s lot's of SMPS type chips that can make dual-rail with very few parts as well.