a friend of mine is making a set top box to run of a bus's 24 volt power supply (basicly a computer , but not using standard hardware , well acorn chipsets are probably not standard....). anyway , he mentioned in an email IC's called Simple Switchers that hes going to use as dc-dc regulaters. hes a physics masters student and he's built set top boxes befor as part of his masters. hes going to tell me more about it on thursday at the pub , i'll get back to you guys about his opinion on the viability of these IC's

(p.s. he also gave me this link , although most of you probably know about it anyway....