Linux Graphics Manipulation Tools
The Gimp Bitmap Photo Editing for Linux - I've used this, its very similar to photoshop, but not nearly as user friendly. Definitely worth checking out though. PythonCAD Cad for Linux - Haven't tried it yet. Inkscape Vector Artwork for Linux - Works well!
Linux Photography Packages
jalbum - This looks pretty cool, I think it generates web-based albums. Albumshaper - This looks amazing! Ah it creates web albums too. The resulting HTML is a little iffy. Works well for the most part. Gallery2 looks like a good server option, meaning the galleries are dynamically generated with the help of a db. Gallery2 is amazing! Curator is more like Albumshaper - just run a script on a directory, and it will build the html and thumbnails and all.