Newest version, includes updated keygen, version 1.7 (which adds support for Vegas Movie Studio HD 9.0)
Tested on my own systems, confirmed working, virus-free (If antivirus reports virus, trojan, or whatever it's false positives.) If you experience problems with activation, please leave a comment or pm me, I'll try to resolve it to my fullest extent.

Instructions:
Extract after downloading, read the README file. The readme that I wrote is the solution to a majority of problems associated with the activation process.
IMPORTANT NOTE: For Vista/Windows 7 users, run the keygen and the installation as an Administrator user.
Even if you're on an Administrator account, you must run the program and keygen as an Administrator. How? By right clicking on the said program, click "Run as.." or "Run as administrator" in Windows 7, select an Administrator account, type the password if required, click "Ok"

Please download the version that is meant for your OS, meaning Windows 64-bit should use Vegas 64-bit, same with 32-bit. (Well, actually 32-bit Windows can only use 32-bit programs.) There is a problem currently with thekeygen not being able to register Vegas 32-bit onto a Windows 64-bit environment. However, you can still try to install the 32 bit version, as some members reported successfully installing both versions. Try it only if the 64-bit version does not register on your Windows 64-bit.
Getting a "Requirements not met" error during installation of Visual C++ 2008 SP1 Redistributable? The below link should solve it.
Some common mistakes that people make are:
1. Not running the keygen and Sony installation file as an Administrator account
2. The keygen is set on default, meaning the Sony Vegas option isn't selected from the drop-down box in the keygen.
3. The keygen isn't placed in the Sony folder or isn't directed to the right directory to patch.

[img]http://t1.gstatic.com/images?q=tbn:ANd9GcTb7vfT38Cym9I2Df-WT4Gdib-IfZ1PEcEQR4cl62I6NB6x-yE&t=1&usg=__Ozqn3jndwIJb43jEfHDFHZazavM=[/img]