I dug around a bit (quite a bit actually).
Initially I tried installing enthoughts python (EPD 7.0) it all looks nice and self-contained. Oddly enough though, one of the things I needed to run (spyder, check it out, brilliant IDE if your playing around with python in the natural sciences) would segfault. I wasn't able to find the problem (yet) so I had to move on.

Then I tried what I should have done in the first place, namely choosing newer debian packages - turns out the dependencies aren't as frightening as I thought:
installed natty's numpy and scipy and so far, all seems to work.

```
sudo dpkg -i python-numpy_1.5.1-1ubuntu2_i386.deb
sudo dpkg -i python-scipy_0.8.0+dfsg1-1ubuntu1_i386.deb
```

with the result that

```
$ python -c 'import scipy; print(scipy.__version__)'
0.8.0
```