Actually a friend of mine in college made an egg timer (in VB) that did something similar. It went something like

while now <> time
   show time on main form
end while
[download]

(or however the hell VB syntax works). It was sort of interesting that his entire machine would literally slow to a crawl while it was running, so as other people have been saying - yes these sorts of loops really will eat all your CPU cycles. {I think a few months later he was enlightened by the VB Timer function} And I'm sure the admin of the server you put it on wouldn't be too happy either ;)