With mobile phones being more prevalent than PCs, retailers would benefit from extending their web presence to the mobile phone. With four times more mobile phone users than PC users, and also the fact that you are most likely to access a site through a mobile phone than a pc when you are on the move, the .mobi initiative is definitely key.
.mobi engaged with the W3C Mobile Web Initiative (MWI) and took a leading role in formulating the MWI Best Practices for mobile content. The practices outlined a number of ways to achieve good user experiences on mobile Web-enabled devices, and recognised several methods of implementing these practices.
Beginning on 26 September, .mobi registration is open to everyone.
Some of the .mobi sites that I checked out and like: (you'll need to access them using a mobile phone)