I'm want to register a small domain name.
I want it to be easy to use from a mobile phone.
The '.com' extension is hard to use because you have to press 'o' then 'm'.
Does anyone has any suggestions of small domain extension names and where to buy?
SnapOverflow
Wikipedia has a list of country specific TLDs: http://en.wikipedia.org/wiki/Country_code_top-level_domain
Some suggestions from there
Each of these allow 2nd level domains (blah.ag instead of just blah.org.ag) and avoid the consecutive number pressing required with .com.
There are many to select from. Here's a good starting place:
http://data.iana.org/TLD/tlds-alpha-by-domain.txt
After that, you need to find a registrar. Many are listed in Wikipedia and other sites. If you're in the USA, .us is a fine option.
Moldova would be a good place to look with its .md TLD. And after a couple redirects from http://www.register.md I was told dmj.md is available for 150 USD. All letters in that domain are the first letters in keygroup. The only way I think one could optimize that is by price.
It seems AD and AG are valid TLDs, but AJ is not. Of course, TA, TD, TG, TJ, TM, TP, and TW are valid TLDs. I'm sure somewhere one could find a cheap registrar with an available three letter domain that costs only one keypress per letter.
.st is a good one for making memorable short domain names
www.nic.st
For where to buy you'll want to look at some other questions here on Server Fault: 31392 for example.
If you're interested in available domain extensions check out this Wikipedia article on top-level domains. Lastly the name of the domain you wish to register really is up to you as it should represent what you are wanting to achieve with the website.
Something like foobar.us would be good. If you are in another country try another extension. .tv would be in the same ballpark as .com, of course.
I have registered domain names with GoDaddy, 1And1, and Dotster. I don't register enough to get any good deals from one vendor so far, so I just go with the current price leader.
Granted, these are usually temp domains that I use, so YMMV.
.mobi Top Level Domain was specifically created for mobile devices. Seem an obvious choice. for more info on .mobi: http://mtld.mobi/domain/faq/general. You can registered it at moniker.com.
I think this is a little bit of a bad idea. If your site is something the user would want to visit consistently, such that typing in the name would create a problem, they could just add it to their bookmarks. And with smart phones with full keyboards becoming more popular, this is going to be a problem that almost entirely disappears within a few years. I would just go with a .com domain name because that's what people expect it to be, and it will be easier for them to remember.