Competitive collaboration doesn't mean people are best friends. On the other hand, it's not defined as enemies squaring off. What it does imply is a recurring dialogue of sorts. Usually both parties benefit from a relationship such as this. They're pushed beyond where they might have otherwise gone on their own. Look at some of the people whom you admire (who do some of the same things you do) and try to make your version better. But take the high road -- this doesn't require a formal letter. It's not a duel. But it might be the spark that you both need: an unlikely meeting, a rivalry, a kind note, an enduring friendship, a nasty note, or just better work. Just think what we'd have missed without these competitive collabo's.
+ Magic & Larry + 'Pac & Biggie + Dan & Dave (not us, the Olympians) + Picasso & Matisse + Ali & Frazier