How do you write NFC tags using a Nexus S?

I have a Gingerbread 2.3.4 powered Nexus S and I recently got some writable NFC tags. So far I can read them as blank tags, but I couldn't find a way to write data to them. All my research has lead me to this article: [Writing tags with Nexus S](http://gibraltarsf.com/blog/?p=13) from January (_before 2.3.4 release_).

Has anyone been successful in writing NFC tags with their Nexus S? Any pointers?