Borders has joined the gold rush into the e-book business via an investment and business relationship with Kobo, the digital reading spin-off of Canadian retailer Indigo Books & Music.  Borders will offer Kobo’s digital books for multiple devices, beginning in the Q2 of 2010. 

And in a sign of the growing popularity of digital book formats, Amazon announced that it had sold more books in digital format than in paper form on Christmas Day, December 25th.  Sales of the Kindle reader are booming, and the many readers given as gifts presumably sparked the surge in digital sales.