Sony is offering current PRS-500 owners the option of trading in their ereader for $50 off the purchase of a Reader Pocket Edition purchase or $75 off a PRS-600 Reader Touch Edition purchase. Or, if you want to keep your PRS-500, they have a firmware update to give it support for ePub format books. This is the format that the newest eBook readers are starting to standardize on. It will also add the Adobe DRM format and add the ability to re-flow PDF documents. Unfortunately, the downside is that you have to ship your reader off to Sony to perform this upgrade. The upside is that they are will pay the postage. One motivating factor for taking advantage of the free update is that without it, starting in mid-December, PRS-500 owners will not be able to transfer new content to their device. For more info check the Sony upgrade page.