For this tutorial you are going to need:

Funhouse Cirquelate Filter
20/20

I used this lovely picture for my tutorial:

Open this picture in PSP and go to effects, plug-in filters,
funhouse, cirquelate and use these settings:

Now you should have something familiar to this:

To make this seamless.........save the picture and open it
in 20/20. Go to image, tile effect and there you have
your finished result :-)
Again, if you think this is a bit too much for a background.....
go for the muted background option in 20/20 !!