I'm not sure if you are looking for someone to actually speak to (using skype or something) or just someone to write to.

I don't think I want to put in the commitment to become a language partner, even though I wouldn't mind improving my Japanese a bit further. If you like, however, I can offer you this:

If you plan to chat here every now and again, and happen to frequent some of the same threads I do (which is quite a few :D), then if you like I can offer advice/corrections when I see you make a mistake in a post. I'm not perfect myself, obviously, but I am indeed a native speaker of English, and I would wager a good deal above average at that (top marks in all my English classes). If this sounds like something you would enjoy, just let me know. :)