We are trying to sort through this as well.
We have used the stairs for a couple of years without attaching them, but they really do move around when the kids start playing. So this year we are attaching them.
We built a little platform to attach them to over the top rail. This works, but I really don't like the look of it. So I'm in the process of trying to do something like jason176 has done (someone else on here has done it and posted pics, that's where I initially got the idea from).
I'm trying to decide the best way to do it:
In this one I have used a 90 deg elbow, and I spray painted the pvc. I still think it looks a little obtrusive.
This is the other way I'm thinking - using some 45 deg elbows instead of the 90. I think I might spray paint a lighter colour than the grey (I couldn't get a beige to match, so I tried the grey - but I kind of think lighter might be better?).
Looks like I'm heading back to Lowes this morning (the plumbing guy thinks I'm crazy).
Any thoughts/suggestions for improving this? Stick with the original?