Picture within a picture effect

Hi,

Suppose I want to show a model twice, but I want
the 2nd view of it to be in a smaller window tucked into
the corner of the main OpenGL window, like so:

-------------------------------------------------------
|                                                     |
|                                                     |
|                                                     |
|                       ------                        |
|                      |      |                       |
|                      |      |---------              |
|                      |      |                       |
|                       ------                        |
|                            \\                       |
|                             \\                      |
|                              \\                     |
+------------+                  \\                    |
|            |                   \\                   |
|   O--      |                    \\                  |
|    \       |                     \\                 |
|     \      |                                        |
-------------------------------------------------------

Is there a standard way to achieve this?
The smaller view of the model will be
altered in some way.

Thanks.