Bicing.cat offers a searchable map of all the bicing stations. However, it doesn’t seem to be very mobile-friendly, and they have not released official mobile applications, though there are unofficial ones for most smart phones (some of them are very good).
An application for Blackberry appeared just a couple of months ago (even when the Bicing service have been working for more than two years). Unfortunately, it requires the GPS to resolve current location before showing any results, and you cannot manually search for a location (by the way, the GPS in my 8900 sucks, it takes forever to resolve). A friend with a Blackberry with no GPS have had problems making it work (UPDATE: there’s a cool app that solves this using if Google Maps works in your phone).
Since I’m a frequent Bicing user, I decided to solve this by myself with this simple web service: www.jpcarrascal.com/b. You just have to type a valid Barcelona adress an submit it. The service will tell show you the nearest stations around that point (within a radius of about 1 kilometer) and will show the number of bikes and spaces available in all of them.
This service is meant to be very simple and lightweight, so don’t expect any fancy maps. It requires you to already know a bit about the system, but it’s quick and works.
I hope you enjoy it.