just wondered
a. how much interest per day the £100millon earns
b. where this intrest goes until its won - camelot or added to the prize money

Don't know about b), but as for a), assuming 4.41% gross (which ING are doing), then whatsthecost.com says you'll get around £338,000/month, which is just over £12,000/day. Except of course you'd have to pay tax on that!