Super cool! Stripgenerator is probably not what you're thinking (although that would also be super cool). It's an online cartoon strip creator that allows anyone with a hankering for making a comic strip to do so easily. I'll get to the actual comic strip building interface in a moment - what is really worth checking out before is all the comics that have been created by stripgenerator's users already. Some of them are really, really excellent.
Linkdoozer always enjoys reviewing websites that encourage creativity by lowering the barrier to entry in their chosen field. Stripgenerator does exactly this, and wow, you gotta see the results. Some are truly, truly AWFUL, and some are pretty good. The former is often hypnotically engaging because the toon is so bad you have to keep reading to see what other horrors are to be inflicted on the unsuspecting reader.
Ok, so Stripgenerator also provides this online strip generating tool - no signup required, which makes it nice to try out. Basically its a huge drag and drop interface with a range of characters, items and text to choose from and manipulate.
This means you are constrained to working with human (or human like) characters so you won't be creating the next Calvin and Hobbes. But, what you lack in flexibility you make up in speed and ease. Once you have planned out what's in the strip, actually putting it together takes no time at all.
Highly recommended for a laugh. There's no excuse now to complain about awful Christmas card gags - make your own.