At last, an online Goodwill where you can search for stuff.
A meta-search engine for ecommerce sites. Search for something to buy and get links to multiple sites where you can get it. Search a particular country, or search globally.
A fairly comprehensive directory of alternatives to Amazon's various services, including Prime.
Everyone's favorite t-shirts from the 80's.
An online bookstore catering to all things occult and all paths. Especially interesting for its selection of left-hand path texts. A good site that brings lots of different books together so you can find the non-mainstream texts out there.
A service that will print high-quality stickers, business cards, and what have you out of images that you send to them. Their prices are quite reasonable, also.
A website that lets you search the catalogs of many independent booksellers for rare, out of print, and unusual books.
A search engine which indexes where you can purchase over 150 million rare, out of print, new, used, and import-only books online.
A website where you can purchase copies of the US Bill of Rights on metal cards and luggage tags.
An online store that specializes in spare parts for and discount UNIX servers and high-end workstations. They have machines and parts for Sun equipment, Dell, HP, Rackables, and Supermicro. A lot of this gear used to be horribly expensive, so hobbyists and sysadmins on slim budgets often have to search long and hard for replacement components.
Temporary tattoos of scannable, information bearing barcodes.
An online catalogue of Victorian, Edwardian, vintage, and steampunk accoutrements, such as sextants, swords, compasses, and other nifty things.