I use Imgur for quick & dirty uploads, and Flickr for anything I want to keep (i.e. build thread and Forester pics, anything from my DSLR). I like Flickr's organization into albums, and I can publish directly from Lightroom to a new album. I really want to keep using it, but they're pissing me off with how few pics you can have uploaded without going Pro, so I haven't spent the $50 to upgrade yet...