There's no hard and fast rule to acceptable bounce rates but here's some context. I have several sites and have worked with many companies on site optimization and have seen higher than 49%. The bounce rate of my personal site is 31%. Strong well established startups I've worked with that get qualified traffic are in the low 30% range. My other misc. projects are in the 40% to low 50% range.
Yes, you can still improve your 49%. Shoot for the high 30-s. From briefly glancing at your homepage there's a lot of glaring things you could be doing better:
As a start...
-Have one clear call-to-action that resides in a easy to see button. Right now you have several that are encompassed in easy to miss text links. As a visitor I'm not sure what to do to get started.
-Use graphics that show what your company does. Right now there's way too much text - people don't read, you've got about 3 seconds to show them what you do, and graphics are a visually compelling way to communicate this.
-Your logo is hard to read, and the value prop in your tagline isn't differentiated enough. (90% of social networking services can describe themselves using the same line). Think about your site's individual value prop and communicate that.
-Work on layout. Your current design looks like a template that's 5 years old (sorry!). Get a designer (99 Designs) to make you something good. It's worth it. This page is begging for a redesign.
-Test and iterate. Use Google Site Optimizer (free) for a/b testing and/or UserTesting.com (cheap) to get more info on how real people react to your site.
Good luck!