With all the cool powertools at our disposal these days, it’s very easy to overlook the simple, yet very practical, basic handtool. I would put a spring clamp in that category.
The three I've shown here are from my latest Harbor Freight adventure. These work along the same lines as a clothespin ... only bigger and sturdier. I was able to find three sizes, which is great. You wouldn't hunt rabbits with a bazooka. (I wouldn't hunt rabbits, period.) You wouldn't clamp a small object with a 4-inch clamp!
These clamps are ideal for helping hold glued pieces in place until the adhesive sets. They also can clamp a metal guide to a board to help those of us who have trouble cutting straight lines. Another thing I like about these: they're padded so they don't leave scuffs, dents or other marks on the objects you're working on.
I'd have to say though that my favorite thing about them beyond their capabilities -- the price. I hit a sale. The 4-inch clamps were $1.87 each, while the smaller ones were 99 cents and 59 cents respectively. That would be incredibly hard to beat in my book! I bought several of the smaller ones and a pair of the 4-inchers. Just like hands and feet, it's good to have at least two.