More literally, does anyone know of a way to physically read papers on a Kindle? I've never been able to reformat even simple two-column PDFs into a format suitable for ereaders. Calibre seems like a good start, but I get mangled results. I end up printing stuff out. Which is OK, but I'd like to have the option.

Even something as basic as trimming ridiculous margins seems rather difficult to accomplish. Is there a software package that'll make this easy?