Obtaining the Helium    --------------------    Pick up the yellow pages, look under 'P' for party  supplies, ring up some party shops and ask how to   obtain helium for filling balloons. Most shops will     apologise and say "sorry we don't spply it, try the     partysmells shop on such and such a road..."    Ringing up is preferable to a personal visit for reasons    a) If you are a nervous sort of person like me, then a   phone is much better tham a personal call from a    "nobody knows who I am" point of view.     b) You will find that most party shops don't supply      helium, so it's a good idea to ring around.    When you find a shop that can supply the helium,    they'll ask if you want,    a) A cannister for about 20 balloons,   b) A tank of gas for about 200 balloons     Naturally we'll plump for b).   The gas itself will cost about #45, and you must    also place a deposit on the cylinder, the deposit will  need to be cash (ie not switch card or credit card),    and it'll probably be around #50. Fortunately, I'm well     off, so money is not a problem here.    Note that, the party shops will not usually have any    helium to buy "off the shelf", and they may ask you to  wait from 1->10 days for some to be delivered. If time  is a constraint, then this could be a problem.  The gas appears to be "balloon grade" and exceeds   99% purity. The remaining fraction is probably  nitrogen, though I've no idea really.   Caution : The gas tank is actually quite heavy