I got the Ikea Stenstorp cart for Christmas. It's the perfect size for extra counter space. It has wheels on one side, so it's pretty sturdy but easy to roll out of the way. The shelves are stainless steel so it looks nice. The color is a weird off white that I might have to paint someday, but other than that it's very practical. I oil it several times a week since it's so new. I have to admit I haven't actually taken it out of the kitchen yet-- I just got used to moving around it.

Go for it! I bought a butcher block island about 10 years ago and still love it. Mine is solid wood with two drawers, a wine rack, and a shelf - not to mention the expanse of prep space on top. It's also been amazingly useful in 3 kitchens so far. When I first got it, I had a small, galley-style kitchen with the counter, cabinets, sink, and appliances running along one wall. I used it along the opposite wall for both prep and as a breakfast bar with stools. In my next apartment, the kitchen and living room were one open room with almost no counter space on the kitchen side. There I used it to create more of a division b/w kitchen and living - it also made cooking for guests much more fun b/c I didn't have to stand at the kitchen counter with my back to the living area. And, even though our current kitchen is pretty well laid out with a large, L-shaped granite counter, we still use the butcher block for extra prep space and storage.

We have Ikea's 'Dacke' island - its a little on the large side, but our kitchen has room to accommodate it, and it almost doubles our counter space! There's also lots of room underneath for a smaller rolling cart, if you need it.

I have a small kitchen cart from Jysk that has been awesome. Space for just a few wine bottles, two shelves and racks on the end for olive oils and things. And a towel rack and granite top.
Much as I like my kitchen cart, man, I'd love to have one of those solid wood butcher blocks someday...

For those of us in the more rural areas, Big Lots is the closest thing we have to Ikea...My mother has this island on wheels made of bamboo w/ a stainless top. It looks great in person.

http://www.biglots.com/Furniture/item.aspx?cid=12&scid=39&iid=6677

I have the Ikea Stenstorp, too. It works great! I wanted to be sure I got one that was actually counter height.

Boos butcher blocks! They are kind of spendy but they last forever. And, I actually saw 2 on Chicago's CL last week for $200.

My movable island is technically a bar which I found in a Habitat Restore. I paid $200 and saw it a week later in a catalog for $1500- score!

It has fabulous storage and a marble top. Since I bake, I love the top for rolling out dough. It's all about what you want to do with it. Incidentally, I was looking for a butcher block one when I found this one.

Yes, when I was shopping for an island I noticed some of the Ikea ones are different heights. It's important to have one that is counter height for comfortable working.

From a hotel surplus store in Atlanta, I picked up an old in room bar that used to be in a Ritz. For $99, I got a gorgeous Drexel Heritage piece with a white marble top, along with a really, really old mini fridge that used to inside.

My dad added wheels and a little height to the piece, taking it up to about 35". We're replacing the back (since the original back had holes for the fridge ventilation and was intended to be against a wall) and I'm planning to paint it black to make it blend more seamlessly in my more mid-century modern kitchen. It's a better island than I could have dreamed of and having a real marble counter for making bread is incredible.

I once had a very small, 10x10 foot kitchen that was very inefficient to work in until I put a butcher-block table (about 18x30 inches) in the center. It was that perfect "landing" place for taking things out of the wall oven, for chopping, offloading groceries, etc. My current kitchen has an awkward L shape, where one leg has a small galley kitchen, the other is just a blank wall and a passage between the dining room and the back hallway. But I found a new IKEA Varde unit that's only 15.5 inches deep by about 5 feet long, with a butcher-block top and stainless-steel shelves. Works perfectly along that spot, with shelves above. It could also be an island if you covered the back side of it with something more attractive than masonite. The Varde line has some very useful island pieces, depending how big you want to go.

I have a John Boos island with a stainless steel base, which would be the first thing I drag out of my house (after my husband and child) if it was ever on fire! I love the versatility and durability of it and the fact that it can move with us to every new house we live in.

I've had to bring my own counter top with me to the last two places that I've lived..first was a rental apartment with a huge kitchen but no surface area. The second is a rental house that i live in how. In my first apartment I was considering finances very heavily, so I bought a buffet sidetable that I found for $35, refinished it, and used it for a year. When we moved in here, the buffet got used as an actual side table and we returned to craigslist for a marble topped kitchen island. It's 2 X 5 and hands down the most used surface in our kitchen--and in fact, it's the largest surface in our kitchen!

Being a Container Store employee, I can suggest two great kitchen island options with Butcher Blocks.

Our elfa drawer system has a optional butcher block top. The drawers are interchangable and the whole unit can be on wheels. http://www.containerstore.com/shop/kitchen/carts?productId=10014855

InterMetro is also a great option. You can create a kitchen cart with a butcher block, and even add additional shelving (as well as wheels). http://www.containerstore.com/shop/shelving/interMetroreg/bestSellingSolutions?productId=10000968 or http://www.containerstore.com/shop/kitchen/carts?productId=10005343

The quality is top of the line and will last years longer than anything from Target (or even ikea)