Finally someone else wants to talk about this topic! I have been fighting with this for a long time. Since 2009 we have about 60K outstanding (some of this does include work comp and MVA stuff so the number is going to be less).

People walk away from deductibles. People when emailed last year said I can't believe you are still trying to collect, I figured you would forget about it and let it go.
When I first started my practice, I was just so scared of not having patients and people getting pissed off. We never used a collection agency. Last year we have a bunch of money outstanding too. Now I don't care if we piss off patients and they go somewhere else for their ortho/sports med care, they can go there, give them the headache and learn that they won't get my care anywhere else.
So I have now started collecting 150 bucks towards their deductible up front before the girls bring them back to the rooms. We tell them that we are going to collect the copay and 150 towards the deductible up front when new patients make appointments or patients who haven't been here in a long time make appointments. We had one girl who came in and was upset about it, we simply let her know that we have been chasing money every year from people who stiff us and we are not saying she would, but this is our policy. ANother kid kept saying he understands what deductible is but his insurance always pays everything. We won't budge on our policy now. If you want to be seen, you pay, you don't want to be seen, you are welcome to not be seen and we will cancel your appt. So far since January 3rd, only those two issues but both ended up paying and being seen and said they were happy with the visits.
At least we figure this way, instead of chasing 220 per visit we are only chasing 70 of it. That way they also don't think they owe so much later. I will keep you all posted on how this goes.
As for the credit card thing, there is a dermatologist in NY who wrote a great article in the washington post or NY times about how he switched over. He said he lost a few patients, but the amount that he collected without issues was totally worth it.