Inkscape and svg2svgt
If you want to make an icon for S60 3.0 you are supposed to make them as SVGT, and to help with that the SDK contains a utility called svg2svgt. This is written in Java, and it's wonderful installer generally fails to install (at least on the 3 PCs I have tried). There is a workaround for this though which works, and is included in the release notes (though who ever reads those). Anyway, generally what happens is that it complains that it is not compatible with the Java 1.3.x that is by default installed on most Windows. It doesn't recognize even if you have later JRE installed. Anyway, the solution is to put JAVA 1.4.x in your PATH.
cmd
c:>set PATH=C:\program files\java\jre1.4.x\bin;%PATH%
then run the installer for svg2svgt from the command line.
c:>\Symbian\9.1\S60_3rd_MR\S60Tools\svg2svgt\installer\svg2svgtconverter.exe
Hey presto, it installs.
So now you look around for a way to make a SVG, and really there is only one good free option, and that is to use Inkscape. You duly design whatever you want and save it in Inkscape, and then run the svg2svgt on it. Hey presto, it looks nothing like the icon you designed in Inkscape.
What has gone wrong? For a reason explained here by Greg_Jokiel the svg2svgt doesn't parse the style attribute used extensively by Inkscape to set the colors and other things. The end result is that your icon looks nothing like you expected. shapes are the wrong color or disappear altogether. Greg_Jokiel gives a solution in that link, though it would be a pain to do by hand even for one icon. Anyway, I created a script svg2s60 to do what he recommends and make the Inkscape files parsable correctly by svg2svgt. No guarantee that it works correctly for all (or even any) files, but it worked correctly for my icon.
Updated 01 Sept 2007: "here" link fixed