Actually, cell phones and other electronic sources CAN be harmful —mostly just bothersome, though.

A pretty simple application (free) which generates random passwords of ANY length is described at http://www.scribd.com/doc/82904349/Random-Integer-Generator-Password-Generator
and may be dowloaded at ftp://ftp.bu.edu/pub/mirrors/simtelnet/win95/math/randint7.zip

Mergers aside, some basics of black holes are presented at

There is a nontechnical discussion (and some speculation) on black holes at