Indeed a good idea, in fact, the circuit is essentially the first project my ex-school's Yr10 electronics class makes - our design also incorporates a battery clip and two pins out the bottom to plug straight into the power rail (longs stips) of a breadboard. It saves on a countless number of lost/stray 7805's and minimises the chances of miswiring, especially given that some students are not so well versed in breadboarding!
ylp88
