It's possibly the most persistent myth about the iPad: No Flash support.
Competitors like to trumpet it to let you know that they give you a "fuller web experience." iPad newbies express concern that their new device will be horribly hobbled. People come to jailbreaking forums asking if there's any way to get Flash by jailbreaking.
Let's ignore the fact that Adobe themselves have declared mobile Flash dead and that the majority of the web has already moved on to HTML 5. The fact remains that there are some sites that still use Flash heavily - Facebook games, photo editors, local restaurants that haven't touched their site since it was built in 2004. Are iPad owners really sacrificing this chunk of the web?
It is true that Safari, the built-in web browser, doesn't support Flash. And it was true that when the iPad was introduced, there was no way to get Flash. But the iPad is nearing two years old, and has hundreds of thousands of apps built for it - do you really think nobody thought there was money to be made in a Flash-supporting app? Of course they did, and of course they found a work-around - by running the Flash through their own servers on its way to you.
In truth, iPad owners have several options for Flash browsers (no Jb required):
Puffin - This is the Flash browser that I personally use. To be honest, 90% of the time if I come across a site using Flash I just leave the site and find somewhere else to do my business. But I wanted to give Flash on the iPad a try. Puffin works great for video, and slow but acceptable for editing photos and photo books on sites like snapfish. It seems to have some trouble with Zynga games on Facebook, though, randomly reloading at inopportune times. At 99c, though, it's a cheap way to check out the occasional Flash site on your iPad.
Photon - I haven't tried it myself, but Photon gets very good reviews for speed and handling of a variety of Flash sites, and seems to be extremely popular. Popular enough that according to AppShopper it hasn't once gone on sale since raising its price to $4.99 in August, but if you need regular and reliable Flash it may be a good investment.
iSwifter - Don't let the Free tag fool you - iSwifter only gives you ten minutes of free browsing at a time to check it out, after which you'll need to pay $4.99 in-app for the full browser. I took the free sample for a short spin. iSwifter is designed with Flash games in mind specifically - it definitely handles Zynga better than Puffin. But if you're looking for more general Flash support, it comes up short on websites it hasn't been specifically optimized for.
SkyFire - SkyFire was the first browser to bring Flash to the iPad, and is still popular. However, its capabilities are limited to Flash video, not interactive content. If that's what you need, it's what SkyFire was built to do and according to reviews it does it well. But if you might want to use some interactive Flash content as well sometimes, $4.99 seems like a steep price for a fraction of the functionality of Photon.