I too agree with the boiling and baking of wood collected from the outside environment. You never know what sort of critters might be on it, especially if you collected from an area near a pond or stream. Bleaching is also a plus, and if you are worried about bleach absorbing into the wood, soak it in tap water conditioner/dechlorinator afterwards as a safety measure. I also perfer to use driftwood I find on the beach, it is usually already pretty well stripped of bark and bleached of tannins. Soaking/boiling it will remove salt residues, and if there are salt water parasitic critters on it, they won't thrive in fresh water.
Wild grape vine is also a pretty neat thing to use in a tank, and easy to obtain, and much better to collect since it is considered an invasive species in some areas. It comes in lots of twisty shapes as well. Other trees I've seen reccomended are apple, cherry, hickory, sycamore, polar, maple, and oak. I've never seen softwoods or pines reccommended. Use dead branches, they're better.
Or go to a scrap lumber yard and see if you can find pieces of untreated wood. They might just give it too you. Then you could sand and drill it into any shape you want. I'd still clean it though with some bleach and a good scrub brush.
~~Colesea