Everyone that has said Sonic Care, I would definitely agree. Just picked up the E5500 and is working great. Love the tingly feeling after I brush. Beeps every 30 seconds to tell me to switch sides and such. Expensive, but well worth it, imo
http://www.walmart.com/catalog/product.do?product_id=5184609
As for toothpaste, I heard no normal toothpaste works (well, not the ones that say they will whiten your teeth). Just find a toothpaste that says its ADA (American Dental Association).
As for strips and such, I heard great things about 10-day kit.
http://www.amazon.com/Crest-Whitest...ef=sr_1_3?ie=UTF8&s=hpc&qid=1218939535&sr=1-3
If you want something easy and no money, try to swish (NOT swallow) hydrogen peroxide (2% that you can buy nearly everywhere). Yes, this is the same stuff your mother use to put on your cuts and boo boos when you were a child. It really does work. What's the best thing about doing this? The fact that not only does it whiten your teeth, but also gets rid of bad breath, and cleans your gums extremely well (I use to have bad gums, where my gums would bleed. My dentist said I needed to brush really good with floss and stuff. Now that I use peroxide daily, my dentist says how fantastic my teeth look).
Some things to note, hydrogen peroxide will degrade the enamal in your teeth, so watch out.
As for other home remedies (if you want). Dip your toothbrush in a hydrogen peroxide, and dip it in baking soda and then brush your teeth. It works really well too (very strong though).
And just to note, for those saying don't do hydrogen peroxide, understand that all those whitening kits have peroxide in it too.