Yet another Poundland deal...I know...but I think this is worth a mention...needed a 15A blade fuse for the car, looked online at Halfords and Maplin and they were around 40-50p each. Went to Maplin but (fortunately) they didn't have any...then while doing the rest of my shopping went to Poundland and saw they had this pack of 20 fuses for...a pound.
The H4 bulb set they do also has two fuses included...never noticed the fuses before!
Larger image here http://www.scenes.co.uk/fun/P1092418.JPG
Worth remembering if you're about to blow your fuse!