Gaboogie is organizing a contest for developers to mashup their voice-application Lypp with Highrise. There are some cool prizes up for grabs including a $3,000 Apple gift certificate for number #1 and free service from Lypp and Highrise.

They got some cool ideas to get you going, like “Integrated Conference Calling within Highrise, Scheduled Calls, Click to Call Contacts in Highrise, Call-back Task links, just to name a few”. Get programming!