Sky HD box Hard Disk Upgrade
Something which has puzzled me about the HD box, is the small amount of 'personal storage', if you have Sky HD you are going to want to record programmes in High Definition, considering that an hours programme is 5-6% then 160gb isn't going to go very far!
There are various options with the HD box, including an external SATA drive (avoids removing the warranty void sticker), or if you prefer a tidier setup, an internal 750gb hard drive. Other alternatives are a Western Digital WD5000AAKS (500Gb) which is popular, or WD10EVCS.
Don't forget that you can use Sky Copy Plus to copy your recordings to your new drive, and to format the new drive correctly if it's over 500gb.
Sky have been a bit more canny with the HD box, obviously realising that a lot of owners upgraded the disc in their Sky plus box, and have a placed a "warranty void" sticker over one of the screw holes for the hard drive mount.
As with any modification it's all done at your own risk.
A full write-up of the disc upgrade can be found here - http://www.morlocks.co.uk/disc-change-hd.htm