Version 1.55 beta of California megamod was released on 2 December 2009, and here are the links for downloading:
(Links updated 8 march 2014)
Please read installation instructions on the download page before trying to install.
Please, before starting installation check the filesizes because many bugs encountered was just because corrupt/incomplete files (if you see any warnings while decompressing then it means that the reported file was not succesfully downloaded, so download it again). Also be warned about the problems that may happen if your internet browser automatically renames downloaded files (usually adding numbers between brackets at the end of the name, and so causing that the unpacker/installer can't find all parts).
Appart from a lot of graphical improvements, thousands of new textures, new vehicles, weapons, peds, clothes, tattoos, more realism, etc, etc, This megamod includes several different gamemodes (.EXE) for playing Grand Theft Auto San Andreas in singleplayer mode, each gamemode may have some different vehicles, peds, weapons, and/or maps, some of this gamemodes are:
california megamod is compatible with SA-MP (but will have no mods when playing samp)
For more details visit the official website: Mods-gta.blogspot.com
it's just amazing, I can't say more
cool!