I'd like to (re)announce our Arduino ProtoShield.
http://conductiveresistance.com/products-page/diy-kits/arduino-protoshield/
Our shield features:
- Long tail pins (for stacking)
- Screw Terminal blocks for all pins
- A prototyping area including power rails
- A Power select jumper to power the shield from an external source or from the Arduino Power supply.
- 3-Pin header vias for plugging into servos or other actuators for digital pins 2-13
We started selling this several months ago, but I thought I'd come here and announce it. I feel it's a solid shield with strong value for prototyping. Thanks for looking 
-Aaron E.
ConductiveResistance.com