My hard drive bit the dust rather spectacularly on my 2011 15" MBP. Luckily, I have a model without torx screws, so I popped it open, put in a 240 GB SSD I had lying around, and did and Internet boot into Lion recovery.
I used Disk Utility to format the drive, one partition, Mac OS extended, encrypted. It downloaded Lion, but after that first reboot, I've got a grey screen with a no entry sign and a spinner. It's not changed for 20 minutes.
Is there anything I can do? Is it not possible to us an SSD? I have other hard drives. Was encryption the mistake?