First of all: I don't think 49% is a particularly horrific bounce rate, but like all things, it depends on context. Conversion rate is much (much!) more important.

Second: looking at your home page, I can see lots of opportunities for improvement, all of which can be A/B tested.

For example: your "Today's photo" widget is tiny-- probably half the size of the third-party ad I got served by Google on your page.

You might want to talk to a designer, to get started.