I had one other thought on the cause of this. If they are blinking more from dimly lit to well lit (versus on and off). This is typically be an alternator cutting in and out. When the alternator cuts in, additional electricity flows to the bulbs, sometimes causing a notieable difference in brightness.

Sometimes this is normal, but if you are noticing an excessive difference, you should probably get your alternator/battery checked out.

Let us know whatt his turns out to be.

I don't have a super-techie answer, but do a quick check to make sure you haven't accidently hit either the 'emergency flashers' or the car alarm. This actually sounds like the car alarm. To turn off, I believe you can either manually turn your drivers side lock to the right using your key.