[George1902]

To paraphrase Douglas Adams himself...

A towel, it says, is about the most massively useful thing an FRC hitch hiker can have. Partly it has great practical value - you can wrap it around you for warmth as you await the start of a regional in the cold morning hours; you can lie on it out in the sun during your lunch break; you can sleep under it up in the stands; use it to cover electronics while drilling or grinding; wet it for use in hand-to-hand-combat; wrap it round your head to ward off noxious fumes or to avoid the gaze of Big Mike (a mindboggingly stupid animal, he assumes that if you can't see him, he can't see you - daft as a bush, but gives very ravenous bear hugs); you can wave your towel in emergencies as a distress signal, and of course dry yourself off with it if it still seems to be clean enough.

More importantly, a towel has immense psychological value. For some reason, if another FRC participant discovers that a hitch hiker has his towel with him, he will automatically assume that he is also in possession of a cordless drill, a tape measure, electrical tape, zip ties, surgical tubing, allan wrenches, socket wrenches, electrical connectors, PWM cables, spare pneumatic cylinders, etc. Furthermore, the FRC participant will then happily lend the hitch hiker any of these or a dozen other items that the hitch hiker might accidentally have "lost". What the FRC participant will think is that any man who can go through a six week build period, rough it, slum it, struggle against terrible odds, win through, and still knows where his towel is is clearly a man to be reckoned with.

It's been a while since I've read the novels, but that's what they say as near as I remember.