Ben over at EngadgetHD has documented the 2 hour procedure to upgrade a stock TiVo Series3 250GB hard drive to something a bit more roomy. If you’d prefer a little more handholding, Weaknees and PTVUpgrade sell both upgraded Series3 units and larger Series3 replacement drives. (As does the TiVo Community Store via PTVUpgrade, with a 15% discount through Sunday.)
EngadgetHD writes: The new challenge in upgrading the drive on the Series3 is the fact that it uses a SATA drive instead of IDE. The next problem that SATA presents is the lack of support by the MFSTool bootable CD or PVTUpgrade CD, some SATA controllers support IDE emulation mode, but otherwise we will have to use a different boot disc. We ordered a Western Digital 500GB replacement drive because we didn’t want to have to solder the power cable to fit a normal SATA drive, plus 500GB drives can be found for around $200 which is much less than the $400 that Weakness charges.