he's a biter!

cujo has been biting more and more lately, and i don't know how to curb this behavior. he bit my finger hard enough to break skin the other day (although just a tiny bit), while i was just sitting there eating. he tried to bite and claw me today while i was trimming his nails. he was trying to bite very hard, luckily i have a very wide, thick leather watchband and his teeth were on that instead of my arm. he was trying to claw with his back feet too, but i was wearing a sweatshirt so it didn't do much good. he tries to bite when he's hyper and crazy playful, too. he is 7 months old.

what can i do to stop his biting? today after his nail clipping i had to put him in his carrier for a time out, and he calmed down, but i really don't like this whole biting clawing freakout thing. i didn't let him get away from me while i was clipping his nails until he stopped struggling. is that good or bad? i didn't want him to think he can bite to get away.