I've just started using Shoptext but I think it is the new wave of samples. You first have to sign up for Shoptext here. Once you've signed up they will text you a code to enter on your registration page. Enter in the code, your mailing address and you're all set. I skipped the credit card info and billing address since I don't intend to buy anything from them, just get FREE samples. There is a place to click "skip" when you get to that screen.
Once you are done registering, you can start texting for freebies. The codes below are the ones I could find and were still valid when I posted this. Please be advised that standard text messaging rates apply. I think many people have a text plan nowadays with their cell phone, but if not you'll want to check with your cell phone carrier first to see how much each text message may cost you. I have 50o texts per month with my plan so I won't incur any additional charges.
Here are the codes I found. You just text the code in ALL CAPS to 467467.
CREST - Crest Whitestrips Sample
DISSOLVE - Clean & Carefree Makeup Wipes sample
FIBER - Fiber One Bar Sample (FYI: response comes in Spanish)
You will get a text back asking you to answer a question and then a confirmation text, so in total you receive 2 texts and send 2 texts. You can log onto ShopText after you text and see that your sample requests were received and what the status of the request is.