LogiXML offers their cut down report version for free and normally I don't go for cut down versions but this one is a useable and good cut down version. This tool only works on Windows and requires the IIS web server to be running because that's the web server the report engine uses and you also need the .Net framework 1.1 or 2.0 installed on your machine.
Let me point out that LGX caters for a number of other databases and SQL server could be its main target but it works pretty well with MySQL producing some good reports in no time at all with features including cross-tab reports, drill-down and drill-through reports.
The other tool that I tried out is Agata Report. Agata is open source and runs on both Windows and Linux and I found that although it lacks the fanciness of LGX Report you are able to produce your reports with relative easy.
You can also export the reports to pdf, xml etc which I think is good and the fact that you can go through the php classes was a winner for me.
The Agata website is in both Portuguese and English and may be a bit confusing at times(especially if you don't know Portuguese) but with time you can easily navigate to the areas you want once you get to know the site a little bit more.
The other tool that I never got time to play with but which looks good is Ariacom Business Reports which has a
free version for personal use.