With more and more websites are created, then the Generic top-level domains (gTLDs) such as .com, .net, or .org that are nice, short and in accordance with your business becomes much less.
Of course we can switch to using Country Code Top Level Domains (ccTLDs) such as .jp, .de, .ca or any others ccTLDs that corresponding to your country, but it would be a problem if you do not target your site for a specific geographic.
The solution is to select the ccTLDs that are treats as gTLDs:
.ad
.as
.bz
.cc
.cd
.co
.dj
.fm
.gg
.la
.me
.ms
.nu
.sc
.sr
.tv
.tk
.ws
Regional top-level domains (rTLDs) such as .eu, .asia will always treated as gTLDs. For more details you can read the Webmaster Tools Help related to Geotargetable domains here.
Note: Above list updated on July-22-2011 by Google, and the list may change over time.