What Weeblie said and...
Tumble is a pretty good skill, if you don't stay still and have a high enough skill on it, chances are you'll be able to avoid every attack of oppotunity aimed at you. Also, it's pretty useful if you have to peel away to protect some other character, just turn and run.
I don't know about belts, cloaks or staffs but I know that a few pair of gloves that Rawkwin already has helps.
Also, every 5 points dedicated to the skill adds a +1 dodge bonus to AC, which is always nice but don't be caught flat footed.