I've compiled a list of useful links for developing IE8 accelerators.

Accelerator Icon Usage Guidelines

OpenService Accelerators Developer Guide

OpenService Format Specification for Accelerators

Windows 7 Accelerator Platform

Writing an IE8 accelerator in 15 minutes (bookmark on Delicious)

How to write a "Find on MSDN" Accelerator

IE8 Accelerator for MSDN Social Bookmarks

IE8 has been officially released and the download is available.

So why should you download IE8? Well, out of all the new features, accelerators are the best! No, it isn't some trick to load web pages faster. Instead, accelerators accelerate your own web browsing experience. For example, just yesterday, I had to find the meeting location where I was giving a presentation. I also need to pull up directions. After I found the address, here's what I would have to do in other browsers to get directions:

Click 1: highlight and select the address information
Click 2: copy that information (ctrl-c)
Click 3: open a new tab or window
Click 4: enter maps.live.com in the address bar
Click 5: paste the address information into that new site
Click 6: enter, and then view the results

Here's what I do in IE8:

Click 1: highlight and select the address information
Click 2: right-click and hover over "Map with LiveEarth" accelerator, click on directions.

This definitely accelerates my browsing experience.