In case anyone is interested, I've posted an example project demonstrating the use of Lift with the Foursquare Scala API located here:
The example project demonstrates how to implement a venue search autocomplete input field (similar to what you see when you search for places on the Foursquare website) using the jQuery autocomplete widget and a simple REST endpoint to perform the remote API calls. To use it, you'll need to get API credentials from the
developer.foursquare.com site.
Note that I've included a modified version of the Foursquare scala API from that repository, as that code has not been updated in awhile and the response format for the venue search has changed.