If you want to have a personal blog server on your WL-500x you can try Simple PHP Blog. You can find it on http://sourceforge.net/projects/sphpblog/

I have installed it and here you go my impressions:

PROS
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.- Lightweight
.- Easy to install
.- PHP based
.- No database needed
.- No perl needed
.- Plenty of features

CONS
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.- Requires external USB module (WL-500x should boot from USB)
.- Requires no less than 12MB swap
.- Even when it is considered lightweight it takes between 6 and 16 seconds to serve a page
.- Still under development (only beta version available)

NOTES
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I sent a HowTo to "WL-500g/WL-500gx Tutorials" but it seems it was not accepted. I explained all process to install it in detail.