The pseudo-standard "AJAX", which is just a buzzword for Javascript + XML (which was done for years without the fancy name) is a bit tricky at times. For most simple needs, though, the Sajax API makes life extremely easy, especially if you use multiple languages (PHP, Python, ColdFusion, etc). Well worth learning, it makes life just so easy!

There's a company out there that lets you sell everything from clothes to postcards to posters to mugs and mouse-mats with a picture of your choice. All you have to do is upload a picture to them, say which products you want and how much mark-up, and they'll do all of the hard work. And the cost to you? Zilch! Zero! Nothing! What's more, once a month they send you a check with your portion of the income, e.g. if the base price on something is $10 and you sell it for $12 they'll send you $2 for each sale! Pretty awesome if you ask me.