Adobe have just released Flash Player 10.
Update your Flash Player now to get all the fancy new features!

At the time of writing the version number of Flash is 10.0.12.36, and Shockwave is 11.0r465.
You can check what versions you have here.

I discovered after upgrading my Flash to 10 that the sIFR I use on this site (to style my dates), and on a few others was no longer working. This was because the older version of sIFR I was using only detected single digit versions of Flash, so I had to upgrade to 2.0.6 to get it to work again.

2.0.7 is the latest version, which includes support for Flash CS3 and CS4, and it also fixes transparency problems with Safari. Transparency on Google Chrome 1.0 works ok, but doesn’t on 2.0 (yet).