As previously announced, we are planning on turning on gzip compression for stream.twitter.com this week. A gzipped stream offers a huge bandwidth reduction over an uncompressed stream, so if you’re consuming streaming data from stream.twitter.com, we encourage you to support this feature.
For information on how to request a compressed stream, and for a workaround to an issue which Java clients may experience, please consult the gzip streams documentation.
The deploy will happen later this week. We’ll update this post and Tweet from @twitterapi once this change goes live. Note that if you are not currently sending the appropriate Accept-Encoding header, then you should be unaffected by this change, but some clients do send this header without actually supporting gzip - best to double check which headers you’re sending to be sure.
Update (2/14/2012): This is now deployed to stream.twitter.com.