I have a new iphone 4 and would like to sell my 32gb 3gs. I know I can get more through ebay or craigslist but I'd rather just go through an online buyer like Gazelle or CellingPost, etc. I've read recent posts that say Gazelle is reputable but I can't find anything about CellingPost. I got a considerably higher quote from CellingPost then Gazelle. Has anyone sold to CellingPost?