Form-a-drain is designed to be used instead of wood to form the edges of concrete footings (so the concrete is constrained to where you want it). It remains in place after the concrete has set and then performs another function - drainage. Many builders like it because it saves labor time (not having to strip it out after the concrete has set). It has perforations in it to allow it to collect water so it can be drained away. As well as performing the weeping tile drainage function, it can also be a useful venting system to get rid of any radon gas. The fact that it is a plastic molding means that it is more dimensionally accurate than lumber so it can be used as a reference for setting the screeding height of the concrete.
Made by North American Pipe (formerly CertainTeed)
Form-a-drain is only made by one manufacturer - North American Pipe. Other manufacturers will probably in the future do copycat products, but for the moment North American Pipe is the sole source.
As with any weeping tile drainage system it is important to use filter fabric over the holes that let water in. You can either glue filter fabric over the flat faces or you can put the whole Form-a-drain in a regular filter cloth sock.
Form-a-drain is available in various depths (between 4" and 10"). It comes in 12 foot lengths. Personally I think it's best to use the 10", but this size is fairly new so you will need to hunt around a bit to purchase it. I was lucky in that in Washington State there's a good contractor company that could supply me with the 10" size. Their contact details are...
You will also need 90 degree and straight coupler pieces and outlets to connect 4" drainage piping.
A 12 foot length of the 10 inch size is something like $15.
90 degree corner couplers for 10" are something like $5 each.
Straight couplers for 10" (to join 12' lengths) are something like $2.25 each.