Imgur is another webhost. However, there is a risk with using Imgur. Whereas they do allow you to use them as an image host for forums, they do not allow you to link to them from a forum that has a classifieds section. If they discover it, not only will they block you, they will block the entire forum domain. What this means is that the entire TTR website would be blocked from accessing images hosted on Imgur...which would affect everyone else's images on the forum that were linked back to Imgur.
Honestly, it really isn't that big a deal to resize images in paint.net or even MS Paint, as long as you have the "Maintain Aspect Ratio" option selected, all you have to do is change one dimension and the other is automatically resized. In paint.net, I only select the percentage. I generally resize all photos I take to be 20% of their original size before uploading. It literally only takes seconds. I don't specifically change any dimensions, I just indicate that I want the new image to be 20% (or something else, if I want) of the original and I can either save the image with the new size or save it as a new image. Then I upload it to my album here.
