I have made some progress porting my MeterServ application (http://meterserv.webhop.net) to openWRT. I have managed to work out how the openWRT makefile system works enough to add it to the build system and produce an openWRT package for the MeterServ application.
To do the improvements that I want to make to the application though, it needs more work. In particular I don't like Perl, so want to convert the web interface part of it to Python. Rather than go for a completely DIY web framework, I have adopted webpy (http://webpy.org) - this seems like a simplified version of django - you define URLs that you want the application to work with, then point it to a python class that does the processing associated with the user requesting a particular URL.
I have started a seperate google code project for meterserv, because a couple of people expressed an interest in it. I have put the latest version of the software in its repository too - see http://code.google.com/p/meterserv.