[skyzend]

Yup, good move in getting the truck towed immediately ... its not you could have done more damage ... its more likely, you would have done more damage. Especially when you attempt to make your first turn and you end up not quite where you expected.

Is your S10 a 4x4 ... if it is you need to check more ...
There still may be more damage, you need to check that things seem straight. Also need to check that CV joint boots are not split, If they are then its likely better to replace the whole axel assembly with boots already in place. Not much more expensive than replacing the boots and a whole lot easier and way cleaner and less specialized tools.

The answer to you second question is yes you can replace just one ball joint. What can happen sometimes is the grease nipple gets broken and the joint just never sees any lubrication and eventually fails. Usually it gets really worn and shows in the tire wear before failure though, your failure is extreme. Have a look at the other ball joint to see if the boot is in good shape and it is not completly void of grease ... next use a prybar or pickle fork to see if there appears to be excessive wear or play ... probably will be ... I bet when you are doing the replacement it is really "floppy". If it is I would change it while you have the whole assembly apart. The additional cost is not much ... just a bit more of a pain to do.