Sure, a lot of apps are already a bargain at a buck or two, but nothing beats free. This collection of sites, apps, and services will help you find free (and newly free) downloads for your iDevice.
For example, 148Apps Now Free, a Twitter-powered offshoot of app-review site 148Apps, delivers a daily deluge of tweets about apps that have just become free. It's almost too much to handle--but still a great way to discover gratis apps.
Free App a Day offers exactly what you'd expect: a new freebie every day. (One each for iPhone, iPad, and Android!) And although the name suggests otherwise, most of the offers last for a couple days. Still, you'll want to check in regularly to make sure you don't miss anything good. Better yet, sign up for e-mail notification, which you can filter based on categories of interest--a nice touch. Alternately, you can follow FAAD's Twitter feed.
What would an iDevice be without free apps that steer you to other free apps? BargainBin With Push and PandoraBox serve up new apps that are free as well as newly free apps. Even better, they can monitor selected titles (like the pricey GPS navigation apps) and notify you of price drops. I can't decide which one I like better--so I use both!