Guess you may be stuck with viewing these on your PC or laptop. Here's something to think about though... While many eBooks in PDF format are crippled by DRM, if the rights to print a hard copy are enabled you can print it out to another, non-DRM'd, PDF using a PostScript or PDF print driver. If you Google some, you'll have plenty to chose from, though you might want to throw the key-word freeware into your search.
If some people are wondering, some eBooks I've ran across that have been locked with DRM did have the print feature enable, though it's usually limited to a certain DPI resolution; the ones I had were restricted to output at 300dpi, which isn't bad quality.
Just a thought. Good luck!
