I'm doing a lot of projects in the shop this summer (starting with planing 240 fence pickts :S) and so I decided that this stool would be an excellent edition (better than plastic chairs) to the shop.
I increased the length of the legs to 30 inches (from the plan length of 23) and its quite solid with the increase.
I don't have a miter saw, so I did this with my table saw and the outcome was very good. Be sure you use a square to make sure your miter gauge is calibrated before making the cuts.
I used 1x2 and 2x2 (2) furring strips from orange that cost $3.12 and $1.47 respectively. I had some 1x12 scraps around and trimmed one down a bit and glued/screwed 1x2s on either side to make it wide enough.
I didn't fill the holes because filler is a bit pricey for the shop stool.
I think I'll make a round top for it eventually, but for now it does just fine.