Well, I was going to post a question about how one can decide that they don't want any children later in life (especially at a younger age, like ShaniFaye's Dave), but after some googling found out that reversing a vasectomy is apparently a routine procedure with
84 to 90% success rate in restoring sperm release.
So I guess that that is probably a good option if you are reasonably sure that you won't want children in the future. There are ways to reverse your decision if you regret it later. I'm not sure if tying tubes can be reversed... haven't looked that up. But I would agree that tying tubes is a lot more invasive.