With Hildon Desktop now having portrait support, I've made a few simple backgrounds for my N900 that repeat both horizontally and vertically, so you don't get any hard edges when switching between desktops. Nothing spectacular, but maybe someone else will like these too.
First a couple simple fractals
And then some noise that looks a little like space
As suggested, something like the US Woodland camo pattern
I was trying to make something like a wooden table pattern here
Added a simple repeating camo pattern to the first post.
All of these are made in GIMP. The top two with [Filters -> Render -> Nature -> Flame...] and made seamless with [Filters -> Map -> Make Seamless].
The starscape is few layers of [Filters -> Noise -> HSV Noise...] with parts randomly cut out, [Filters -> Blur -> Gaussian Blur...] for glow and again made seamless with [Filters -> Map -> Make Seamless].
The camo pattern is several layers of [Filters -> Render -> Clouds -> Plasma...] and made seamless with the Resynthesizer plugin.