The first time I'd really found out about it was during hunting season one year with a friend and his dad. His dad parked on a hill with the front of the truck facing down the hill, everytime we stopped he always parked on a hill that way, never understood why. Then I realized the 3rd time that he was letting the truck roll forward and letting out the clutch to start it rather than using the starter. So ever since then anytime I drive a vehicle with a manual transmission and I'm up in the hills by myself I always make sure I'm parked on a slight hill in case a starter fails or battery is weak.
This is a great thing to learn anyone who drive's a vehicle with a manual transmission should know how to do this. It saved my ass in town when the bolt fell out of a starter on my 99 Dodge Ram. I had a friend with me and we pushed it out of the parking space and got it going fast enough to get it started and drive it home without the starter.
Not sure that its really hard on the clutch or transmission at that slow of a speed its not really gonna damage anything, but its something to rely on if you have a starter or battery failure.
The bolt on the bottom of the starter on my B2 wouldn't tighten down, I didn't have time to mess with it, so I had to have a shop fix it. The guy wanted to charge me $100 to do it, but he said if I took the starter out he would do it for $25. So I took the starter out, had my grandfather pull start me with his truck and drove my b2 into town to the shop with the starter sitting on the passenger floorboard.
This goes along with anyone who wants to drive should learn to drive a manual transmission, any idiot can put a car in D and go, it takes skill to learn to properly operate the clutch and gearshift, what gears to use when, etc. Even the younger generation of truck driver's I see on the road are really bad about lugging the engines in the semi-trucks. Heaven forbid people had to put down their cell phone, pda, palm pilot, tablet, etc. and pay attention to what they're doing, this is one reason why manual transmissions aren't around much because it makes people actually have to drive their car and pay attention.