Caver?
The traditional method for cavers with compact cameras without a hot-shoe is to cover the flash on the camera with a piece of fully exposed film negative - i.e. the leader piece of an old 35mm negative and use an exteral IR trigger to fire the flash. The firefly
http://www.fireflyelectronics.co.uk/pages/info.htm is what a lot of cavers use. Flash guns such as Yongnous have built in IR triggers and I can trigger one from my TG3 using the technique I just described. The disadvantage of just using a flash gun on its own this way is that they are not as sensitive as the Firefly and you tend to need the front of the flash pointing more towards the camera – which is OK because you really need more than one flash. Because the firefly is a separate unit you can point it at the camera independent of the flash.
I find a small light tripod is very handy and if you start to get serious with this you are going to end up carrying a lot of gear – Chunky over on UKCaving takes around 15kg of gear I believe to get the remarkable shots that he achieves.