Loft and cavity wall insulation are currently subsidised - so if you haven't already got a good deal on your insulation, do think about it!
Look out for Warmstreets - a scheme offered by Nottinghamshire County Council.
In January 2012, Westville insulated the walls and loft in the house that I am currently renting - a couple of hours and job well done, as we can see from the thermal imaging photograph...
The green whispy bits to the left of the front door are where hot air comes out of the boiler vent. The walls themselves are a lovely insulated blue colour!
The red patch on the roof is another vent, but the roof insulation is keeping us warm.