This is the service I use, as do many other ABers:
http://upl.co/
(It's quicker and easier than Tinypic because there's no Captcha thingy involved. Use the 'Direct link' to copy and paste here).
Upl.co can be used for non-image files too. For example, if you had a pdf document you wanted to make available to other ABers, you can upload it in exactly the same way as if it was an image and then paste the file download link here.