Recommend a good slave flash for canon S3?

Can anyone please recommend a good slave flash for the canon s3? Possible one with a bracket?

Thanks in advance

Have a dig around the compact forum, there are a couple of S2 and S3 shooters get very good results from flashs mounted on brackets.

Ideally you want something with manual power settings, as well as an Auto Thyristor sensor.
You will also need someway of triggering it, useing with an optical slave that fits on the hot shoe.

Vivitar, Sunpak and starblitz are 3 of the best well known brands that make a variety of flash units suitable.
But, I have an old Canon flash from the 80s, that includes its own Thyristor sensor, as well as manual settings, and is easily triggered with an optical trigger.
I also have an old Sunpak that has a built in optical trigger.

The best source Iv found is a local trading site, like eBay, but second hand shops also carry the odd old flash.