Resco Photo Viewer for Palm OS looks somewhat promising, if a bit limited in scope.
I want a mini Photoshop for the Palm, one that I can use to create and draw in as well as look at pics. The most crucial image-editing tool for me would be curves, apart from the imagemarking tools such as brush. The few sketchpad apps I have seen are like thin-featured imitations of MacPaint, very 1985.
Adobe includes Palm as a supported OS for Elements, but I haven’t yet figured out if it’s more than a simple album-sync.
While I enjoy the challenge of working in two-bit graphics (see below), it’s sort of like using a skateboard with steel wheels.
This was drawn on an old-at-the-time Mac SE, using the mouse and looking at Chloe who was atop the warm teevee.
In the time I spent using my Visor Prism, I enjoyed using TealPaint for concept sketches and color swatches when away from a desktop machine. That said, it doesn’t offer any Photoshop-like image tweaking capability.