I've certainley had a few posters here influence a change in my POVs before. I know talloulou has convinced me of the pro-life argument. I know some libertarians have swayed me towards their side on some domestic issues, especially regarding states rights. Kandahar has made sense of FTAs for me. Several people on the left, swaying me towards the side of gay marriage, or at the least recognizing civil unions by the government for all and reserving marriage as a private matter. Most of these issues I would say I was swayed, simply because I had never before engaged in conversation about them and reading the debates I found myself agreeing with the arguments they put forth.
And conversely, regarding issues I did have relative experience with, I have found people even more educated and insightful on these topics that share the same general view point with me, and thus I admittedly become more tightly bound to that side of the issue because my experiences are "validated" by their study and expertise. People like GySgt, donsutherland, Tashah for their ME views. Someone like rivrrat, who has grown up in the small town America like I did.
I have a lot of varied interests in many things. However I am admittedly not nearly an expert in any of them. The only thing I think I could "teach" on this forum, is about insurance or how to fix an F/A-18 fighter jets avionics. Not really interesting topics. I mostly like to learn from others here, and if it sparks an idea or thought, share that idea with them be they opponent or on the side I am arguing for.