After a brief appearance, the Verizon BOGO deal (buy one get one free, for those who didn't know) is alive once again! You can get the Droid Eris for free once you buy either the Motorola Droid (for $199) or Droid Eris (for $99) at a Verizon Wireless store. The deal is actually available from now until Christmas, so if you're thinking of offering a Droid as gift, now is the time to buy.
On another note, Amazon is offering the Motorola Droid for $149.99 and the Droid Eris for $9.99, so it's actually a better deal on Amazon if you wanted to buy both devices. BOGO or no BOGO, it's a great time to get a Droid.