Sandi --
If you're looking to add fiber to your diet, Fiber One is an excellent source of insoluble fiber. I would recommend the cereal over the bars. One serving (of the ORIGINAL cereal, not the sugary concoctions) contains 14 grams of fiber and only 60 calories. I usually put a half a serving on my yogurt in the morning to add a satisfying crunch. Admittedly, the cereal looks like worms. But I swear -- it's delicious!
Chickory Root is naturally occurring plant fiber but also claims some additional health benefits (like lowering cholesterol).
As far as making your own bars, sure -- you can do it. But I've not successfully made a power bar with more fiber. The modern world is full of innovations that I can't reproduce in the kitchen. However, I do enjoy Alton Brown's power bars:
http://www.foodnetwork.com/recipes/a...ipe/index.html but I still keep my serving size small because they aren't exactly low in sugar.
As a side note, I also like making fiber one cookies for potlucks or cookie exchanges because they're usually a lot lower in calories than the other cookies.
http://www.fiberone.com/recipes/Reci...=43535&cid=406