From PC TechZone:
InstantFeedback makes it easy by running in the background and automatically posting as soon as positive feedback is left for you on eBay. Enter your own comments or use the included ones, specify by region for different languages. If you should get negative or neutral feedback, you will immediately be notified so you can rectify the situation quickly. It can even automatically request a feedback withdrawal from eBay. You can mass-post feedback for everyone who has left feedback for you starting back a set number of days, whether they've left it for you or not. It can post the auction titles as feedback replies to make it easier for people to browse your feedback.
What's new in this version:
Version 2.4.45 fixes a problem when posting feedback from the manual feedback window.