Ideas for topics for your projects

Demo software that provides NoSQL 

Using relational dbs to provide object persistence

Data interchange using JSON or XML. These are used to exchange data for sites using data from web services (i.e. mashups). XML and JSON are topics for week 3 of our course, esp. see p. 365). 

If you are interested in mobile app development: SQL Lite for Android

Ruby is a popular new server-side language and Rails is a popular framework. This would be an alternative n-tier system.

If you are interested in .net programming: .asp and SQL Server as an alternative for the php/MySQL work the whole class did

Data mining

Service oriented--If you know an organization that could use a database or an active web site