I've been studying some of the national semi datasheets on their linear regulators which suggest specific values of capacitors on input / outputs, according to the input-output voltage. Most commonly, the suggestions for capacitor use are indicated in the "Application hints" section of the datasheet (which is normally located within the first few pages of the document) and also within the sample circuits section toward the end of the document. I'm not sure if formulas are provided (I can't remember seeing any for capacitor use).
The most interesting portion of the datasheet that I have found regards the LM317 adjustable regulator, which suggests the use of diodes to protect the regulator from output shorting (located within application hints). I don't think I have seen this diode use in any of the regulator circuits that I have seen on the web. I think it is something to look into, if you're running an adjustable regulator.