I like to saute green beans.  In case it matters for answering, I saute them in canola oil and soy sauce.  I always end up with some of my green beans perfectly sauteed, some overdone and some not quite done. I sit there and stir them every 3 minutes or so while they are frying, but they never distribute evenly.  Short of constantly stirring for 30 minutes, is there a good trick to get them to all cook evenly? 
First off, 30 minutes seems like quite a long time, and stirring ten times seems like it should get things reasonably even. Perhaps you just like your beans really thoroughly cooked, but it does make me wonder if you might be using too small a pan, which would also make it difficult to stir thoroughly and contribute to uneven cooking. So make sure your pan is big enough that the beans on top of the pan are at least keeping warm. And if you aren't already, make sure that when you stir you're really getting the ones from the top down onto the bottom so everything can cook. I've certainly sauteed beans like this, and gotten fairly even cooking without stirring constantly.  That said, you can also save a lot of work by changing your cooking method. Jolene suggested blanching (a quick cook in boiling water, followed by rapid cooling), which will certainly work, but is also probably overkill if you just want to cook them right away. You can essentially steam them in your pan before sauteeing. Simply boil a bit of water in the bottom of your pan, toss in the beans, then either cover or stir constantly. They'll be cooked most of the way in a few minutes, then you can drain the excess water and proceed with sauteeing (no need to cool them). If you get the hang of it, all the water will have boiled off by the time you're ready to move on, and you won't even have to drain them. (And if it boils off too soon, it's easy enough to add a bit more.)  You could also consider simply roasting them. It's not quite the same, but it'll get you even better browning than sauteeing. Just toss the beans with a bit of oil, salt, and whatever seasonings you want, spread them out on a pan, and throw them in the oven for around 15 minutes at 425F. You might want to stir once halfway through, but if they're not piled up much, you can even get away with skipping that. 