We just finished and published out QR code generator at
www.btcfrog.com/qr.
Just enter a Bitcoin address and press "show QR code" to view the QR image as a png.
or press "generate code" to get a piece of code to embed on your website to generate
the image or other such images programatically.
The error correction and size options can be set to other values (it is possible to rescale the final image if you wish).
If you enter an amount and a bitcoin address a "payment of <amount> btc to address <address>" will be generated.
Happy QR code generation
The BtcFrog