- Google Apps: For $50 / user / year, you get email (w/ exchange), docs, chat, reader, sites (intranet) and true real time collaboration. No more licenses to pay for Exchange, MS Office, OCS & IIS etc.
- Amazon Web Services: All the server services (to test & run your software). Comes in a variety of configurations and prices.
- GitHub: For hosting your source code securely and track bugs in real time. Plans start at $25 a month.
So unlike, an IT department, you don't need to schedule a down time for services as Google Apps has 99.9999% uptime (so does AWS & GitHub). Other benefits include portability - you can work from anywhere in the world.
Granted, not all companies can do this - "old school" companies are run by "old" executives who have this aversion to these Web 2.0 technologies - but you can be sure that all the startups that are being founded right now are going this way and that means in the next 10 to 15 years, you are going to see IT departments disappearing.