Voxeo is at Google I/O this week, and one of the products we’re showing off is Tropo. Telephony and SMS seems like a big complicated problem to most people, and they’re amazed when they see how easy and powerful Tropo is.

A decade ago, telephony required all sorts of complex hardware, specialized programming languages, and knowledge of how phone systems worked. Voxeo was founded to make it easy for developers to build applications that run over the phone. The last few years have seen telephony adopt web programming technologies like VoiceXML and web services APIs. We’ve also seen the costs of implementing real time communications come down. Coupled with the rise of hosted and cloud services meaning you don’t need to install or set up VoIP servers, an age of real-time communications is dawning.

More and more consumers are beginning to prefer text over voice. A whole generation is just as likely to communicate over text messaging, IM, and social networking as they are to pick up the phone. If the last decade was about the rise of the telephony developer, the next will be about the demise of voice as SMS, IM, and social media take precedence in consumers minds. To help developers with this transition, Tropo takes the concepts we’ve developed for voice applications and applies them to communications in any form.

Applications developed for voice with Tropo work over SMS, IM, and Twitter, with no additional programming required. Sure, you’ll probably want to tweak the output to be more appropriate for the medium, but it’s not strictly necessary.

Want to see just how easy it is to build a Tropo application? Take a look at our mashup with the San Francisco Bay Area Rapid Transit (BART) schedules. Using your phone or IM you can see when the next train is due to arrive at the station of your choice. Call or SMS (407) 374-9954 or send an IM to bartdemo@tropo.im with Google Talk to try it. You can even talk to @tropobart on Twitter. Tropo treats Twitter as an IM network, sending all @mentions to your application just like an instant message would be.

The code behind this is written in Ruby and can sit in our cloud or on the web server of your choice. Other sample applications are available covering everything from simple games to directory assistance, to checking into Foursquare.

Get started building your own application today by creating a Tropo account. Tropo is 100% free for developer usage, so there’s no cost or risk involved in trying it out. You can even take advantage of our world class support, available 24 hours a day.