I have spent the past year getting rid of stuff ... slowly because I have to over-analyze everything. Early in the process I had to make the decision: do I hold out and try to sell it, or do I just pass it on. I decided that the karma from blessing others would easily outweigh the financial reward of a yard sale **because I despise having yard sales**.
I hear you, though, on having difficulty with giving things away when you could really use the cash. I use ebay, craigslist, resale shops, and a local parents' group "for sale" section, for anything that truly has value. Otherwise, I sincerely believe that I will prosper financially and emotionally as a result of gifting everything else. I use freecycle for anything that is questionable, and try to donate to homeless shelters anything that I can. (actually, because I hate to drive, I don't really "deliver" many donations)
I recently heard that there is a flea market/style location in Houston for selling personal items, kind of like an off-site yard sale - I don't have the time or patience for that, but it sounds like a great way to unload big stuff.