There is a upy Webcast embedded into this documentation, presenting a talk on upy by me. Its auditory should match you, although I’m not sure how well I matched the auditory :-).
Here is a small Python shell session:
Python 2.6.5 (r265:79063, Jul 18 2010, 12:14:53)
[GCC 4.2.1 (Apple Inc. build 5659)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import upy
>>> ua = upy.undarray(2, 0.1)
>>> ub = upy.undarray(10, 0.05)
>>> print ua, ub
(2.00 +- 0.10) 10^0 (1.0000 +- 0.0051) 10^1
>>> print ub.printable(format='float')
10.000 +- 0.050
>>> print ua * ub
(2.00 +- 0.11) 10^1
>>> print upy.cos(ua * ub) + ub
(1.041 +- 0.092) 10^1
>>> uc = upy.undarray([[1, 2], [3, 4]], [[0.1, 0.5], [0.7, 2]])
>>> print uc
[[(1.00 +- 0.10) 10^0 (2.00 +- 0.50) 10^0 ]
[(3.00 +- 0.70) 10^0 (4.0 +- 2.0 ) 10^0 ]]
>>> ^D
Python-32(3414) malloc: *** error for object 0x239670: incorrect checksum
for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug
Notice the nice error in the end. Can you reproduce this (on your machine)?