Do you buy related domains early on (.net, .org, similar spellings)?
liranbaron: It's pretty cheap to buy domain names so if you have the $20-$30 to buy the domains do it. Why not.Much better than to have somebody see you, recognize potential and buy your other domains and then demand some $15M for it.
Of course the odds of this happening are quite low, but nevertheless, in the event that you make it it's a small price to pay to avoid the future headache.