My nifty little computer:
It is a sufficiently interesting computer in and of itself.
The OLPC project goals are nearly without bounds. If you do not see a project you like, start it.
In wandering the pages here there was one with three parables. A fourth might be a reflection on an old cartoon. I think it was a "B.C." cartoon that started out with one caveman chipping away on a rock. A second caveman asked what he was doing. The first answered that he was inventing writing. Walking away the second shook his head and remarked "You just made the whole world illiterate". In a way this is how I see projects like this. It may not be as earth shaking as literacy but it needs teachers, materials, books, paper, ink and minds.
 My50000Factorial benchmark:
For years now i have kept a little benchmark in my homedir. I calculate 50000! with the unix calculator bc/dc. Not a quick floating point result but an exact answer. If printed on paper the answer would hang from a second story window with a pile of paper on the ground. More than 20 years ago this little benchmark would take more than a week to run on the 68010 system I had access to at that time. After a "yum install bc", on this little OLPC box the exact same script ran in less than 25 min. Then I ran the test using python and the obvious result was to "rpm -e bc".
 Pippy and Python
One of the baseline activities of the XO is Pippy. Pippy is an interactive python environment that lets the student select an example. The example is copied into an editing window that is mouse friendly. Below the edit window is the standard out that is generated when the "run" button located between the two windoes is clicked. It is a clever way to get started with Python as it requires almost no prior knowledge to run or edit.
Python has a place on the OLPC XO that hearkens back to the UCSD P-System where the OS was interpreted p-Code and the programming language was Pascal. Python today is a worthy replacement and unlike shell scripting does not depend on a 'bin' of helper tools like sed, awk, diff etc. to get a task done. Python is a rich and powerful programming language.