see http://www.euse.de/honig/beescale/graph.php
my monitoring prototype uses the weight cell you are proposing here.
the [hive design][2] is from a urban bee keeping community project called "bienenkiste.de". they re-invented and upgraded the [Krainer Bauernstock][3], a design from an 18th century beekeeping book describing beekeeping techniques in the Balkans. my [data][4] is also downloadable. but sorry, my [how-to][5] and [todo-list][6] are only in German language. i would like to answer translation questions or assist a translation.

my next step will be a temperature sensor matrix inside the hive (7x5x3 sensors in the 60x40x20cm hive breeding space). it will produce plots like [here][7] (i tried to connect to those developers but they didnt answer). i will probably use [heatmap.js][8] to visualize data. my plan is to improve visualization techniques to be able to show an animated semi-transparent 3d-heat plot of the hive - instead of only (animated) 2d-cuts through the hive. hardware-work, electronic circuits and data-transfer and -storage will not be my problem. i need help (or more self-education) when it comes to improving visualization algorithms and coding.

further links: sorry, i'm not allowed to save more than two links because i'm a new user.

Hey Mark!
Yeah while connecting to the hiveeyes project I found your blog and the weight cell setup which looked really promising!

Looking for visualization and coding i have two suggestions for you:
1. you could try to contact the guys from hiveeyes.org - they are thinking about that already (though i don't know if they have anyone yet for doing the job)
2. We'll be developing a frontend in the next months. It will be open source and probably it should be easy for u to adapt the thing. @brianzable is running a project called HiveLife - that might be interesting for you aswell - he said it's easy for him to include external data into his frontend - so maybe he has a solution for you

concerning the 3d data visualisation, u may have a look into that program:
http://jpgraph.net/

For beekeeping with Top Bar Hives (TBH), knowing how the weight distributes between the front (typical cluster and brood area) and the back (honey stores) is important. Thus with a weight bridge having sensors on the corners of the hive you can monitor not just the total weight, but also weight distribution.

@macsun: good point. same with bienenkiste hive system: the honey department is behind (not under or over) the breeding space.
but i tried flexiforce pressure sensors before we decided to use one weight cell. the problem was calibration. we couldnt manage to get it done. i would like to give away my sensors to enable somebody else to come up with a method of calibrating those things and actually get a weight out of them...
see http://wbk.in-berlin.de/wp/blog/2012/02/flexiforce-fsr-experimente/ (sorry, in german)
more interesting is hacking body scales: but we were not able to decrypt the signals from the system of a 9€-scale we tried to hack... see http://wbk.in-berlin.de/wp/blog/2012/03/gewichtssensoren-billiger/

@ron: i will check hiveeyes and hivelife.
3d-plotting: jpgraph is no alternative because it doesnt produce 3d. it is just another javascript-2d-visualizing-library with a business plan in the back. so i prefere dygraphs for line charts and heatmap.js for 2d-heatmapping.

There might be some information about weighing corners from the car racing industry as they do this to balance the cars before racing.

-- mark