If you're on Verizon FIOS and have one of those old 160GB DVRs. There's a little known link on their website where you can request an upgrade to a new 500GB. The switch out costs $40, but they delivered mine a day after I ordered it. Instructions below.
So go to www.verizon.com/fiostvcentral and log in.
Click on My TV.
Click on the the sub menu that says STB or set top boxes.
On the right side you'll see a small ad that says "do you want to get more out of your DVR" or something to that effect click on it and fill out the info.