Rooting the Acer Stream is pretty darn easy. It can be done using an application you install on your phone, called z4root.
This application isn't available in the market, but thats a small hurdle and easy to overcome. All you need is a file browser, and your USB cable
File browser -- if you don't have one, I suggest Astro. There are many others, but Astro is very simple to use and I highly recommend it to those who might be new to the Android platform. Search for "Astro file manager" in the Android Market, and install it on your phone.
Then it's a few easy steps to root:
On your computer, . Read the first post in the thread carefully, and download the file that's attached. Also, notice the donation link if you feel like passing a few dollars to Ryan.
Attach your phone to your computer, and just like you would drag a music file or picture to your phone, copy the z4root.apk file to your SD card. You can put it in any folder you like, just remember where you put it
Unmount your SDcard from your computer, and unplug it.
Go to menu>settings>applications. Make sure the "unknown sources" box is checked. Then go into the development settings, and make sure USB debugging is checked.
Now open your file manager, and find the z4root.apk on your SD card. Press it, and choose Open App Manager (Astro gives this choice), then press the install button.
One last step you may want to do if you have chosen to permanently root is install busybox. Search the Android Market for "Busybox by Stephen (Stericson)" and install it. Busybox provides commands like copy and paste to the shell (the inner workings) of your OS.