Olla pot irrigation was described in writings from 1st century China, so it's not new, but it is well-suited to the Texas climate. The concept is simple...unglazed clay pots are buried in the soil, filled with water and covered. The soil wicks the moisture from the pot as needed; during periods of rain, the seepage stops - overwatering is never an issue. Groups such as Global Buckets have been paying attention and have incorporated clay pots into some of their designs.
I love the water conservation aspect of this product. Texas summers are brutal - keeping your garden watered can be a pain; miss a day and you may just have cooked it. Because the irrigation with these pots is underground, evaporation is at a minimum. By mulching the surface you can protect the soil even more, and help maintain those moisture levels.
As with any gardening tool, prices range from expensive to downright cheap for the DIY model. Any unglazed pot will do; the wicking has to do with the saturation level in the clay. Here is a very detailed DIY video - I think I see a group workshop on this in the future as it might be easier to do this as a group to see how it works. If you're interested in joining us to try this out, leave a comment so we can gauge the interest.
On a personal level, I purchased an Olla from Dripping Springs Ollas to try in a 4x4 bed. When I buried it I realized it was bigger than I thought, so I've mounded soil and mulch around the neck of the jar. You can see how the clay is damp just above the mulch line - the deeper you bury it, the less evaporation you'll see. As my bed ages and the cardboard underneath decomposes, I may be able to dig it deeper, although when the plants get large, they'll shade the pot and it will still be easy to fill. You can also add fish emulsion or liquid molasses to the jar for slow release.
It's funny how things come full circle; these were being used 2000 years ago. I guess good ideas never go out of style!