ACME wants to add a registration feature to their site as well. Nothing fancy, but users are requested to fill out a form and have that information stored in a database that can be searched or sorted so that they can find basic demographic information about their audience. Later on they may wish to integrate this into something that would track their visitor through the site as well. If you can do this in flat html files, they'll be happiest.
Investments R Us has hired a series of analysts to provide advise on certain stocks for their customers. They will want to set up a database for the analyst's opinions. When a visitor to the site searches for information on a stock not only will they get the current quote, but items from the database as well (if there are any for that particular stock.) You'll also need to build a password-protected, web-based publishing tool for the analysts to enter new text into the database.
Blockmonster has signed a deal with a major music magazine to provide new content on their site. The magazine will provide you with the last 7 years of copy in a consistent tagged ASCII format. Roughly 160 pages of copy a month. Extract the text and dump it into a database that can be searched or sorted by the "keyword" field included in the copy. Once this is done, you'll need to add a feature to the rest of the site so that when a user pulls up an album listing, it will link to any articles about the artist. Use the database software and servers that you already have for this site (i.e you don't need to factor software and hardware costs into this).