First, I wish for U.S. Federal Government apps. Open up wsAPIs for the budget, to the library of congress, to congressional behavior, to America's Job Bank, to Commerce Business Daily, IRS, SEC and the hundreds of regulatory agencies, OSHA, USGS, environmental databases. We spend billions to collect and host an amazing collection of useful data and services. Some are web exposed. wsAPIs may be the key to making them more useful to more people in new and exciting ways.
Second, Monster.com (NYSE:TMPW). More than half of all time spent in online job searches are spent on this site; comparable to Amazon's and Google's mind share. Expose job posting and listing, resume posting and listing, and company profiles. Watch new ways evolve for fitting people to work. Can't you see looking for the resumes of people who read both "C# Essentials (2nd Edition)" and your column?
Just for fun: iMDB, the internet movie database (owned by Amazon so you may have some pull there).