If you know you're going to eventually buy a stand mixer you could buy just the bowl that fits it now. You can usually buy those separate. Then when you do get your mixer you'll have an extra bowl for it. And since you say you bake a lot you might be craving the extra bowl eventually anyhow.

Faith is right - what you need is a Big Tall metal Bowl. Also key to improving you mixing neatness is making sure the Bowl is U-shaped like this one:

http://www.bedbathandbeyond.com/product.asp?order_num=-1&SKU=13918554&RN=213

rather than the wider mouthed regular round bowls, like this one:

http://www.bedbathandbeyond.com/product.asp?order_num=-1&SKU=11401643&RN=213

The wider ones are better for non-mechanical mixing techniques like folding whipped egg whites into chocolate mousse as they allow long fluid strokes.

The taller ones keep the mess of a hand mixer better contained. I know cause I have the same problem!

Go to your local restaurant-supply store (nobody should ever buy kitchen equipment from anywhere but there), and get some stainless steel mixing bowls. They're dishwasher-safe and come in tons of sizes. Even a huge one will cost you about five bucks.

Coscto sells a set of heavy duty stainless steel mixing bowls. they have a rubberized bottom to prevent sliding, come with lids and are $30 for a set of 8. Epic deal.

Ztuttle beat me to the punch. I couldn't agree more; Costco's rubber-based metal bowls are the best. Deep enough for hard-to-mix doughs, sauces, etc. Tough enough to deal with scratches and beatings from even the roughest of whisk-ers. And the rubber covers the base enough to prevent the bowl from moving. Seriously incredible.

I love love love my metal bowl from Ikea - it wasnt expensive, has held up very well for the past two years and I throw it in the dishwasher all the time.

I use my farberware, straight sided pots. The handle makes pouring out the batter or applesauce easy, the straight walls keep the blender from throwing batter over the sides and it won't tip over like the round bottom bowls. My 2qt pot is ideal for muffins, the larger one for applesauce.

I had the same problem, so I bought tall metal mixing bowls. Sometimes, when creaming butter and sugar a little of the mix escapes but not as much as when we had shallow, wider bowls. My mum also bought me a tupperware bowl/jug that comes with a lid with removable middle section, meaning there will be a collar around the bowl when I mix- yet to try it out though.

I like these: http://www.cooking.com/products/shprodde.asp?SKU=768490 (I got mine at Kohl's). They're pretty enough to use as fruit bowls, and they have nice high sides.

I recently received mixing bowls from Crate and Barrel that I use more than I ever imagined.
Check them out: http://www.crateandbarrel.com/family.aspx?c=670&f=36196

Good luck!

I am a big fan of 3 types of bowls. I use Pyrex most, great for mixing, you can get lids with them for storing, extremely durable. Make great double boiler bowls.

As already suggested, restaurant supply store stainless steel bowls, variety of sizes, super cheap.

Oxo mixing bowls with rubberized bottom, wide bowls, bottoms great to keep the bowl from moving all around when mixing.

I also think the first suggestion of buying a stand mixer bowl is excellent! If you know what kind of mixer you'd like someday, I've purchased a 2nd refurbished bowl from KitchenAid.com very cheaply, and can't tell the difference between that and my original bowl.

I have the same bowls as marisab, as well as some metal bowls, and some old pottery(?) type bowls that are hand me downs for probably 2 generations. I don't like the metal bowls because they're so light - they slide easily around the counter when you're trying to use them.

The ones marisab are nice and heavy, and I found them at Wal-Mart (labeled as "serving" bowls), sold individually for $5-7.

The older ones, which you could probably find at a thrift shop or garage sale, but I am reluctant to put them in the dishwasher.