Originally posted by sarteck:

AFAIK, you cannot train Sneak by auto-running.
Also, your Sneak skill improves a lot more if you are within visual range of a mob, so there's that...

[Edited for spelling]

x10 experience, but only if the mob stays unaware. If you're within sensory range of an aware or aggro mob, you don't get the increased exp rate. Then again, it's actually easy to create situations where you don't have to worry about alerting any practice critters.