Develop an application that will run in the background of your Android phone and will monitor your level of activity (sleeping/sitting, walking or running, say) and display this information.
Platform: Android SDK

Once you step on a bus you can help others track the progress of the bus by broadcasting your location. Develop a system that would take the place of an expensive Bus Éireann solution by sending your bus location to a server. The bus' movements can then be accessed by others waiting for the bus.

Platform: Android SDK

Cloud computing is a distributed computing technique that is growing in popularity. Using one of the frameworks for distributed computing (most likely Hadoop) develop an application that crawls the web looking for CVs. A database can then be built up of who has expertise in what skills.
(See PH03 also.)
Platform: Linux Desktop + Hadoop (or Google's MapReduce)

The Google Go language (www.golang.org) claims to be well suited to getting "the most out of multicore and networked machines".

Develop a distributed application (possibly PH02 above) using Go the language.
Platform: Linux Desktop

Project Code: PH07
Project Title: Photo Mosaic Wizard
Project Category: Software Application Development
Create a collage of photos from a database so that the composite has a likeness to a chosen picture.

Some examples: http://www.artensoft.com/ArtensoftPhotoMosaicWizard/screenshots.php

For an illustration of how it can be done using dominos go to -
http://4c.ucc.ie/~hcambaza/page5/page5.html

The program could be packaged as a web service but this is of secondary importance here.

Racetrack is a very enjoyable pencil-and-paper game (see wikipedia's description of it for more information). Develop an application that will run on Android phones to play this game electronically. Platform: Android SDK

Develop an application that will determine high and low tides for coastal spots around Ireland that will run on Android phones. Platform: Android SDK.