I can't vouch for these, but over the course of the last few months the following links have shown up on my RSS radar, and they look promising. Take a look for yourself.
Spin JS, which turns textboxes into clickable number up and number down boxes-
A jQuery based Color Picker-
Easy Google Map Marker Creation-
Thanks to Ajaxian and Web Resources Depot (see sidebar under useful links) for making me aware of these resources.