Google XML Sitemaps with Multisite support is just modified Google XML Sitemaps plugin, originally written by Arne Brachhold.

Some time ago I was employed to work on Gnosis.hr site, which needs to drive two sites on one WordPress installation – one for Croatian version and another for the English one. Everything seemed fine until I realized that Google XML Sitemaps isn’t working with Multi site installation.

My modification changes this – you can have numerous sites on one installation and each of them can have own sitemap.

Installation:

• Install “Google XML Sitemaps with Multisite support” through the WordPress admin (or download)
• Create “sitemaps” directory in directory where you’ve installed WordPress
• Make “sitemaps” writeable”

That’s it. 99% percent of work is done by Arne so, thank you Arne. I hope that our projects will merge into the one in the near future.

UPDATE: Plugin is no more supported since there are many other plugins doing the same thing.