You'll need to use a PC, but you are now free to make your own Portal puzzles.
If you thought the puzzles in Portal 2 were a little too easy – or even if you just want more of them – more challenges are almost surely on the way. Valve has released a beta version of the Authoring Tools for the PC edition of Portal 2, and they’re now available to owners as a free download via Steam. The client comes with an updated version of Hammer, the Source level editor, and will allow modders to build levels with existing Portal 2 assets and/or independent materials.
The tools are the same as those used during the development of Portal 2 and can be used to create both single-player and cooperative puzzles. Valve will further provide some sample maps to familiarize players with the technology and to help get the creative juices flowing.
Of course, many of the original creations will probably suck, but a few of them should be just as good as those produced by Valve and it’ll be fun to see what kinds of tasks the community is able to come up with. At the very least, I don’t think anyone is going to complain about having something else to do in Portal.