Firefox only: The eBay Toolbar lets you search eBay, access your account and more, all from within Firefox.
Currently, eBay's own browser toolbar is an Internet Explorer-only product. This Firefox equivalent serves up just about every eBay-related tool you can imagine: search (including options to search eBay Motors and Half.com), favorites, and quick access to various buyer, seller and My eBay pages. The toolbar also offers a boatload of useful links, including price-comparison sites, consumer reviews, shipping tools and more. In short, if you're a Firefox-running eBay user, you'll definitely want this handy toolbar.
The eBay Toolbar is free; it works wherever Firefox does.
The eBay Toolbar [My Friendly Fox]