Yep. I picked it up a day ago when I saw this thread about it being on sale. Basically you create "tasks" which are a list of "actions". There are a ton of actions that can be completed (too many to list here). Then you create a "profile" which is basically a set of rules of how to complete a task. You have a ton of options of which types of rules you can create.
You can see some examples of profiles others have created here:
Profiles - Tasker Wiki
Here are the ones I've created for myself:
1) When headset is unplugged, media volume is muted to prevent it making unintentional noise.
2) If I miss a call from my wife between 8am and 5pm during work days, it automatically sends a text saying that I'm in a meeting. I didn't want to base the event on my calendar (which I could have done) because sometimes people come into my office and we have impromptu meetings.
3) If I tap-and-hold the camera button, a menu will appear with my favorite phone contacts. Tapping the menu item will call the person. There are also menu items for launching the dialer app, camera app, and camcorder app.
4) Speaking of camera...this is probably my favorite profile. If I turn my phone into landscape orientation (clock-wise), it automatically launches the camera app.
5) On Saturday and Sunday between 8am and 11:30pm, I turn the ringer volume all the way up. I usually like having the ringer on during the weekend.
6) When I'm near my home (based upon cell towers near my home), I turn on WIFI. If I leave my home, WIFI turns off. You can also use GPS for this type of profile, but it would eat up more battery. Using cell towers won't eat up any additional battery. But I'm still determining whether this profile will work properly.
7) If I'm in a meeting at work, I mute the ringer.