Unfortunately this is not a solution for many of us, but for those in the US, Green Dot Moneypaks are worth looking into.
Basically, it's a debit card refill that's purchased with cash, but you can also use these moneypaks to fund Paypal accounts. To get one, all you have to do is go to your local store, pay with cash however much you'd like to fill, and then you receive a card with a code on the back, that can be used online.
I was thinking that this is an ideal way for US citizens to exchange money for Bitcoins, considering the fact that CIM is slow, can get lost, and Paypal has chargebacks that are beginning to create problems. This seems like a nice medium ground. Instead of Bob and Alice exchanging with Paypal, Bob sends Alice bitcoins and Alice sends Bob the moneypak code, preferrably through an escrow or trade service. Once the moneypak is used, Alice cannot use the funds on that card or get them back. If you have a greendot debit card (around $5 a month, but they can be found for free depending on how much you deposit a month), you can deposit moneypaks right onto the card and use it for ATM withdrawal, or as I said, deposit them right onto Paypal for instant funds without fear of chargeback.
For the buyer, this is nearly just as easy as sending cash in mail, and much faster considering they can hop online right when they get the code and send it to the merchant/trader. Most grocery/department stores will sell them.
The only downside I see to this is the fact that moneypaks cost $5 each, maximum $500 per card. For small trades/payments, the option really isn't of much value considering the price, but for anything over $100, the ability to instantly pay with cash and inability to create chargebacks adds a lot of value to an option like this, not to mention easy and simple ATM withdrawal if you get a Green Dot debit card of some sort.
https://www.moneypak.com/https://www.moneypak.com/StoreLocator.aspx