If you use Google Sites as part of Google Apps, you can now map the sites to your domain. Instead of having to link to ugly URLs like http://sites.google.com/a/domain.com/wiki, you'll be able to customize the addresses and replace them with subdomains like: http://wiki.domain.com. "The new location can be your domain home page or any sub-domain in your domain, and can be set up on the Web Addresses tab of the Sites service settings in your Google Apps control panel," informs Google Sites Blog. You can find more details in the help center, which notes that private sites are redirected to the standard URLs.
Many people expected something different from Google Sites and the name doesn't help the service too much. Google Wikis would have reflected the true intention of the service. "A wiki is a website designed for collaboration. Unlike a traditional website where pages can only be read, in a wiki everyone can edit, update and append pages with new information and without knowing HTML. Wikis are great for all types of collaboration, from writing documents and managing projects to creating intranets or extranets," explained JotSpot's intro tour.
Wikis created with Google Sites allow a very limited amount of customization and you can only embed content from trusted sources like YouTube or Google Docs. One of the causes for the lack of customization is that the wikis are hosted at google.com, instead of a separate domain like googlesites.com, and a script could easily compromise your Google account.