Note that some of these are too simple for a project and others may be too complex. Treat the following merely as a collection of ideas from which you can pick some you like, combining them to get a project that both interests you and is sufficiently challenging from a technical viewpoint. You are encouraged to stop by during office hours to discuss any of the following that may interest you.
See also: Project Guidelines. As mentioned in the guidelines, innovative projects are encouraged. While the number of truly innovative ideas in your project is not a primary factor in deciding the project grade, picking an innovative and unusual project has the significant advantage that you will be less likely to get bored with the project and will have more fun working on it.
Online store of some kind (sim. to amazon.com and friends) books, CDs, electronic music (e.g., mp3), ... catalog, browsing, shopping cart functions, payment, fulfillment, ... Library DB Search collections, check status, checkout anc checkin, incorporate existing system Room scheduling distributed authorization very low maintenance easy report generation clickable, annotated map as UI Personal Information Manger (PIM) contacts, addresses, phones, ... appointments diary to-do list Something similar to the Elisp package bbdb.el Meeting scheduler XML in a RDB/ORDB UMD Parking lot information DB best parking based on destination, cost, etc. fallback lots special cases ease of update Restaurant/Cafe/Bar/Pub/... reviews DB Consumer reviews database (similar to epinions.com). Class schedule, prereq, comments, grading, etc. DB CS Personnel and/or Machine DB (simple) Info about every CS "entity": people, machines, labs, vending machines, rooms, ... Bank of AVW (simple) Debit, credit, billing, interest, ... Job postings DB Openings, contacts, references, reviews, requirements, bidding, ... USENET Data Miner (hard) Import data from USENET into RDB (fact table), import data from other sources for author info, group info, org info, ... (property tables), mine Data mining Web server logs (hard) Similar to USENET Data Miner Email (SMTP) server using a DBMS focus on novel functionality enabled or simplified by DBMS USENET (NNTP) server using a DBMS focus on novel functionality enabled or simplified by DBMS Storing graph data in a relational DB? DBMS survey(more work but easier work) Implement a very simple project on N DBMSs (preferably open source or free) for N > 3 and report experience. DBMS interface survey Implement a very simple project using M libraries or APIs (e.g., Perl libraries, Python libraries, and ODBC and JDBC bindings for C++) for M > 3 and report experience. Historical weather DB retrieve, parse, and store weather information from NWS and other *public domain* sources over time; implement browsing and querying that can be used to discover trends, records, trivia. Auction database Similar to eBay.com Historical traffic DB Similar to historical weather DB. Netnews server (similar to DejaNews) enhanced querying, consistency, security and control. Personal finance DB (similar to Intuit Quicken, Microsoft Money, etc.) Download data from the Net in popular formats (QIF, OFC, ...); analyze in interesting ways; trends; bill payments. Write an ODBC or JDBC driver(ambitious). Database for WMUC (service). Integration projects: Combine information from three or more public databases and present it in a nice format. (This component can be added to many of the above projects. For example, you could integrate weather information from a number of sources.) Data Warehousing and Data Mining: Collect gobs of data from some source, support queries, discover trends, etc.