OneAlert is a lightweight and powerful reminder system with simple calendar. To create new reminders just type something like this: "Call Katrin in 15 min" or "Send report next Fri 15:00".
You can mark an individual day or number of days with specific color. Reminders can be repeated a number of times as well as set to reoccur according to advanced recurrence pattern.
If more details and settings are needed they are also available under "Advanced >>"button. There are different alerts can be set for a reminder (like play a sound, run application or send e-mail).