System Scheduler is simple tool which can help you automate programs, display alerts, and more.
You could use it to just launch certain programs at a defined time, for instance (once, every few minutes/ hours, daily, weekly, monthly, even yearly).
You can also set up System Scheduler to display pop-up alerts, and again these can be one-off prompts or regular reminders about some important task.
While this is much the same as Windows Task Scheduler, System Scheduler does have a couple of useful extras. In particular, after launching an application you can also send it simulated keypresses, so helping you to automate all kinds of tasks. (You could perhaps open your email client, create a new message, attach a specific file and send it somewhere, for instance.)
System Scheduler also includes a Window Watcher, an interesting tool which allows you to carry out some action based on the state of your program windows. If a particular window exists then you can close it, say; if it doesn't exist then you can fire up that application; if a program has hung then you can restart it, and there are plenty of other possibilities.
All this functionality is supported by a very lightweight scheduler, which consumed less than 2MB RAM when running in the background on our test PC.
And if you need more, a Professional build adds plenty of extras. The program recognises many more events ("On Idle", "On Cease Idle", "On Wakeup" and more), has many extra actions (including shutting down and rebooting local and remote PCs), runs as a system service for greater reliability, adds a "process watcher" and "file watcher" for even more automation possibilities, all for $30. The Splinterware website has more.