Most TeX distributions (TeXLive 2008 and MikTex 2.7) have now been updated to support SyncTeX. The option is activated with the -synctex switch at the command-line as follows:
pdflatex -synctex=-1 mybook.tex
This command produces a file name 'mybook.synctex' which can then be used to perform PDF<->TEX synchronization. The file can be large so you can instead produce a compressed version (mybook.synctex.gz) with:
pdflatex -synctex=1 mybook.tex
The SyncTeX patch that I've developed is now maintained in the main development branch of SumatraPDF; it is part of the latest official release (version 0.9.3).
I will still continue to publish my own builds of SumatraPDF to my website (the executable is updated regularly even though I am not posting about it): at the moment the only difference with the official release is the presence of a dialog box to let the user configure the inverse-search command. (In the official release this is done by passing command line parameters to SumatraPDF.exe.)
I wrote a short documentation to help you configure your favourite editors for synchronization with SumatraPDF.