[gadgetguy32]

Anyone know why after jailbreaking on 3.0 you cannot change your SMS theme or keyboards?

[blkcadi]

Most have not been updated for 3.0 yet. As far as SMS, do you mean the bubbles? They can be changed via SSH.
SMS Bubbles 3.0 change:
/System/Library/PrivateFrameworks/ChatKit.framework
Just replace Balloon_1.png for SENT and Balloon_2.png for RECEIVED.