over 140 web buttons for inspiration and thought that you might find the collection useful as well
related resources
Bullet madness is a list of 200 bullets, arrows and icons
CSS Tabs and CSS Navigation Menus Showcase (over 70 entries so far)
http://www.intersmash.com/300images/
I roughly estimate that for every six web sites I scoured, I was able to acquire one graphic image. I visited only Fortune 1000 company sites, major online retailers, well known blogs, top advertising, publishing, and design agencies, technology and software industry leaders, and the very largest online news publishers. Approximately 1800 web sites later, I have this collection of 300 of the most interesting, unique, and beautiful formations of pixels to display.
107 Add to Cart Buttons of the Top Online Retailers
Graphic Design Blog 
Very nice examples. Keep up the good content.
Thanks for the info..Very informative!
Pinetop Rentals
This is a nice collection of buttons. For those who wants create their own button with easy, I will suggest Cool Button Designer. Cool Button Designer can generate buttons for all three states on the fly, mouse over, mouse pressed and normal states. It give you ability to control the light and reflection, add icon to your button, to gazillion of shapes, etc… Very nice software to create Web 2.0 style button. Cool Button Designer also generates you the HTML code for you to use.
You should try it, its not a joke, and with 3-5 minutes you can build this button from scratch.
Google for Cool Button Designer.