All very tentative, but here are some of the options:
Add more features to RedInk, the online marking and code review system we've built over the past twelve months.(Now full)
Building a plugin for Blackboard to calculate and display statistics on the grades being given out by TAs in large courses (Java programming, lots of integration, customer is profs at U of T).
Building a map-based visualization of data about theatre performers and playwrights in Shakespearean England for the Drama Dept. and the library (DreamWeaver, web programming, GIS).
Adding new features to DrProject (Python web programming). There are lots of possibilities here, ranging from user-centered views to a progress dashboard to continuous integration tools and real-time documentation generation.
Extending Languify, an open source web-based tool for managing translation and internationalization (Ruby On Rails, web programming). The customer here is a local software startup called Savvica; a student has built a first version this summer, and there's a lot of interest.
Help the folks at CAISI integrate hospital information systems to help the homeless. This one would mostly be Java; it's a very good cause.
Work with Digital Ketchup to build a REST web services interface to a tool that combines data from email and customer relationship management software.
Add some features to BlogScope to integrate with other data sources, and do some of the AI and pattern matching more efficiently.
Sort out the mess that is date/time representation in Python's database interface libraries.
If you're at U of T, have at least two 300-level courses in CS, and a good GPA (3.0 or higher), I'd like to hear from you...