I started getting this question a lot, so I thought I’d answer it in a separate blog post.
Update: This is important. There are certain domains that NIRA has labelled premium — although it isn’t clear which those are, until they release the list. Bottom line is you can’t register those. And you can’t register two character domains either (e.g, bo.ng). You would also do well to avoid names that will be likely protected by trademark. Wouldn’t do to have it yanked out from under you later.
Note that you don’t have to buy hosting from any of them. You can always point your nameservers and host your website on any hosting provider of your choice. Your preferred host will often have the instructions on how to accomplish that.
Update, 10:44am: Not sure how accurate, but I’m hearing again that buying from 101domain might be a risky proposition. You should probably just stick to the local registrars.