For all those people who have
fallen in love with their
best friend, a piece of
advice (yes yes, I know everyone wants to give advice, but heck, just like all the others, mine is
free so you can take it or leave it ;-)
Just as you start your relationship, look your best-friend-now-significant-other in the eye and remind them that up until now, you have been best friends. You have had and shared the best and worst of times and that even if the relationship should end, that both of you will remember and treasure what you have shared so far.
Relationships come and go, but friendships should last forever.
It always amazes me that so many people cannot remain friends simply because they went out together. What a waste to lose a best friend simply because you couldn't get a relationship to work! You should be mature enough to realise that you may not be 100% compatible with someone else, but that surely doesn't mean you can't be friends.