Download here: http://www.omnigroup.com/applications/omnidazzle/

I've been using OmniDazzle since it was in beta, bought a license as soon as it was available. It's hands-down one of the most useful apps I've ever used, especially in the workplace.

As of Wed Feb 25, 2009, OmniDazzle is now totally free.

I'm not sure why they changed the license. When I bought it, I paid $15, and I assume they were still charging the same until recently. I guess by making it free, they don't have to focus as much on fixes/tweaks/updates, although the app seems to be pretty stable... since purchasing 1.0 in June 2006, they've only released a handful of minor updates, even now they're only at version 1.1.

Anyway, all Mac users should grab this utility now. It's both useful and silly, and at $0 the price is just right.

While doing some performance testing for a Tomcat-served webapp, I discovered you can enable automatic gzip compression based on content-type. In basic testing, this resulted in ~65% decrease in data transmitted from server to client. Considering a page with 400k of content, that could shrink down to 100 or 150k total. Good stuff.

A great tool for performance benchmarking is YSlow (http://developer.yahoo.com/yslow/), which hooks nicely into Firebug. Using YSlow I was able to see as much as 80% reduction in transmitted data after enabling Gzip.

Note that Tomcat will not compress content unless the browser identifies itself as understanding Gzip compression, which it does on each inbound request.

Here are the steps to enable Gzip in Tomcat:

1. edit conf/server.xml
2. find the Connector, should look something like this: <Connector acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" enableLookups="false" maxHttpHeaderSize="8192" maxSpareThreads="75" maxThreads="150" minSpareThreads="25" port="8080" redirectPort="8443" maxPostSize="0" />
3. add the following: compression="on" compressionMinSize="512" compressableMimeType="text/html,text/xml,text/plain"
4. based on Connector definition from above, mine looks like this after making the change: <Connector acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" enableLookups="false" maxHttpHeaderSize="8192" maxSpareThreads="75" maxThreads="150" minSpareThreads="25" port="8080" redirectPort="8443" maxPostSize="0" compression="on" compressionMinSize="512" compressableMimeType="text/html,text/xml,text/plain" />
5. restart Tomcat

Reference documentation for v5.5 here:
http://tomcat.apache.org/tomcat-5.5-doc/config/http.html