I bought one of these on a whim from Bed Bath & Beyond the other day (partly because I had a coupon burning a hole in my wallet that was about to expire) and although it sure is a wacky way to make a cup of coffee, I have been surprised at how good it tastes. Because of the way it works, the water is in contact with the grounds for a very short amount of time (less than a minute) and so you get a brew that is very low in acidity and totally smooth. 
 
The only negatives I've found so far are:
 

• It requires a very fine ground for best results and since I use a hand grinder, it's taking me a lot longer to grind enough for a cup in the morning. In the past I've used a French press which requires a coarse grind and is hence a lot quicker. Still, can't complain about the extra exercise. 
• You actually need to apply quite a bit of physical force to depress the plunger which forces the air through. I find myself using both hands, and even so I can feel it in my shoulders after the minute or so it takes to work the plunger all the way down. 

It's worth it in the end though! I like my coffee smooooooooth.....

One happy Aeropress owner here!! (thanks to Jbow...Julien's suggestion).
 
We've had ours for about 3-4 months now and I have to say, this makes the best cup of coffee. My wife & I love our morning (sometimes evening) coffee and we've tried all kinds of machines that couldn't do what this does.
 
We also have an electric grinder (might be good for you to get one James).....makes (fine) coffee grinding a simple task. Our kitchen counter is low enough for us to just use one hand to push down "plunger" (mostly letting it go down without too much effort).
The only downside (for us) is that it only makes one cup at a time (although a fantastic cup it is....).
 
We also use a Nespresso milk frother that heats/froths the milk which really makes it like you're having cafe' coffee (keeps the coffee hot as well). The Aeropress is definitely one of the better $30 we've spent.
 

 

My previous roommate had one and loves his, but there is that one cup thing...

Sorry, as usual, I can't help.  But I would like to try it sometime.
 
Jesse Q. Screed

I once had a pair of pants Martinized, if that helps.

I have had an Aeropress for years. Makes an awesome coffee when using it correctly and with some fresh ground awesome beans. I get good quality beans that have been freshly roasted and store in freezer until needed.
 
A little curious on the need to use a fine grind. I use a medium grind and works great. I found I was doing it a bit wrong until I found this video - https://www.youtube.com/watch?v=48ics7oymw8 I started with this method and have stuck with it ever since. I generally let it sit for a little bit longer before I plunge as I like a nice strong brew. I stop plunging when I hear the sssshhhh sound to avoid the bitterness.

yorolpal
I once had a pair of pants Martinized, if that helps.

I remember those "1 Hour Martenizing" places from when I was a kid.

I use espesso ground/roasted coffee in a drip maker, more grounds less water.  Nuke the milk, froth with a wand style frother.  Sometimes with Baileys ... yum
 
I read you (sharke) talking about a French Press and I've almost impulse purchased one a couple of times.  But not yet.

Isn't the French Press a free weight exercise?  
 
(I'd imagine it's one where you get under the barbell, start to push it up, decide it's too heavy and give up, ya?  )

The French press makes a nice brew but a little bitter and sometimes you feel the sediment in it. That's why you need a coarse grind, so it can't get through the holes in the plunger. Of course the Aeropress uses a paper filter so you don't have that problem. A finer grind gives you more surface area and allows you to reduce the time the water is in contact with the grinds so reduces acidity.

The thing about the Aeropress is that there are all sorts of "recipes" about how to make the best cup. Some people like to "bloom" the grinds first by pouring a little hot water on them (I used to do this with the French press) and others like to use more water than required and stop the press before it pushes all of the water through. Believe it or not there is actually an Aeropress championship in which enthusiasts compete to see whose recipe gives the best cup. If you Google it you'll get some good recipes/methods to try.

One thing I was surprised about is how long you need to leave a kettle of water to cool it to the ideal 170F. The manual says around 17 mins!