*Abuse is defined as you, taking my pictures, and...:

1- Posting them somewhere else and claiming that they are yours.
2- Altering them without permission and then posting them. Even if you credit me. Ask first please.
3- Taking -pieces- of them and using them as internet stationary or whatever without permission.
4- Posting them elsewhere and making money off of them in whatever form, with or without credit.
This is a big one. I'm not making money on my art- you shouldn't be either.
5- Things like that. You shall taste my wrath.

Please note that you CAN use pictures for personal enjoyment (saving pictures is froody just about everywhere, I think).
In fact, you can even get away with using a couple of them (WITH CREDIT AND PREFERABLY NOTIFICATION)
as long as they are unaltered. Abuses can be met with legal action as in the case of #4, or with flames and loss of credibility.
If I don't feel my art is safe, I'll just make it go away, which isn't really a threat, just something that could happen.
It isn't fun for anybody, so just play safe. This is fairly standard stuff, and it shouldn't be hard.
If by some strange chance, you are intersted in a commission, email me.