When I was wanting to try longies for cloth diaper covers for my son I got some free for shipping because he was the right size for some tester longies a work at home mom on diaperswappers.com needed someone to try out.
When Natures Baby Organics was testing it's bubble bath I got to try it out for free as a tester (it is fabulous by the way- http://www.naturesbabyproducts.com/bubblebath.html).
Friday I recieved a Drybees diaper to test for colorfastness. This diaper is actually the most beautiful diaper I have ever owned. It reminds me of an evergreen forest at sunset. Absolutely amazing colors, the picture does even start to do it justice.
Now, being a tester is a lot easier then finding out about products that need to be tested. Sometimes these oppertunities come knocking- and that is honestly how I have been a tester for the above except for the longies which I did go looking for in the diaperswappers wahm forum. However more often they will pass you by without ever stopping and you'll never know the oppertunity was there. So if you are interested in being a tester talk to the companies you are interested in testing products for. If you are wanting to try a new kind of product, go searching for a testing oppertunity. Email the companies or work at home owners. Ask them about being a tester. Tell them you are interested in their products, but just aren't sure yet so would appreciate the oppertunity to test out a similar product should the need arise for them.
Talk to friends and family too, or post about it online in a community you are active in. Just the other day I saw a mom posting about wanting to try out homemade natural soap from a wahm but not having the $$$. Now I am not a wahm anymore, although I have sold my soap in the past. But I pm'd her and am going to send her ffs a few of my complexion bars and some homemade bars of soap so she can try out homemade soap. If she hadn't meantioned that desire in a post she probably wouldn't be any closer to trying out homemade soap then she was earlier this week, instead of days away.