True! I cannot remember the last time I used my landline for outgoing calls.
Giffgaff on the mobile covers me well.
Only problem is that with virgin, I believe it works out cheaper to actually have the landline on your package than not in most circumstances.
Cancelling your phone line could actually end up costing you more per month.
Keep the line, just don't plug a phone into the socket, or just turn the ringer off