Digikam is a free and open source photo management software package for KDE. Many KDE-based Linux distributions either come with Digikam installed or have it available in their repositories. With Digikam, you can import photos from your digital camera or flash memory, organize and tag them, rate them, edit them, and export them to various services or custom galleries.
Three popular services that Digikam can handle are Flickr, PicasaWeb, and Facebook. The first two are social photo sites, and the last is a social networking site. All three support photo plugins used by Digikam. This makes uploading photos quick, easy, and painless.
I am operating under the assumption that you already have accounts on the services you want to use. If not, you will need to register and activate whichever accounts you want before you proceed.