Migration advice

Hello...
I've been using phpweblog for a website for approx. 1 1/2 years. It's been a nice setup and has been fairly easy to tweak/customize.... however...they don't have a whole lot of new features modules/plugins that are being developed and I am hoping to enhance the site a lot more in the coming months.

I've considered using something like postnuke, for the users/mail/forums/modules that are easy to find and plugin. I've use phpnuke and postnuke several times...infact I wish I had known about them before I set up the site with phpweblog. I have a bit of content on my phpweblog site and want to figure out it if it would be easy enough for me to migrate the data from one system to the other. I haven't found any scripts out there that anyone has used to do this with... and was wondering if any one in here has seen anything like this done easily.

I may need to pull out my sql book...and work on a huge script to migrate everything into a different system.

any suggestions?

thanks