Big conference is taking place now, named eComXpo. In any event, a bunch of PPC engines are there giving away coupons. An other accessible coupon for you is from Google AdWords, they are giving away $50 in free clicks for new users. The coupon is available at this web form.
Enter your email address and the URL of the website you want to promote with AdWords, then click "Send me a coupon!" We'll send an email in a couple of days to the address you provide containing a coupon code and instructions for redeeming it and setting up your AdWords account.
Also get your MSN coupon while they last.
Forum discussion at DigitalPoint Forums.