The proper method of regulation for large snakes (really, any potentially establishable invasive) should be on a state by state basis, based on the actually possibility of that animal to establish in the habitats contained in that state. The fact of the matter is that reticulated pythons just can't establish in the US. They have far too particular needs during breeding and egg development to sustain any sort of population in the wild. While the USFWS uses bogus science and ecological pretenses for this ruling, the reality is that this is being driven by immense pressure by people that are against pets, of all kinds, period. By dividing communities into small segments, they can creep up on the more mainstream.

I'm not against intelligent, science-based regulation. I have no doubt that Burmese pythons, and probably boas as well, should be heavily regulated in Florida. But the claims made in the USGS report that was the sole science behind this ruling are total junk. They claim that Burmese could survive in more than a third of the country, yet in 22 years they have never been seen north of the subtropical band of Florida that the Everglades sits in.

Hell, in the final rule, USFWS notes clearly that the state fish and wildlife services (AWFA), and the Pet Industry Joint Advisory Council (PIJAC) were against the addition of any of these animals to the Lacey Act. They pushed for close work with the states to make appropriate legislation at the state level. They also suggested USFWS should take a stance as being an emergency response and support component of regulation of large constrictors rather than implementing a Lacey Act injurious species addition.

In addition, as others noted below, positive licensing would go a long way. The process of applying for a license and passing some sort of test of knowledge and preparedness would be more than enough of an impediment for most casual buyers who just want a big snake because they're "cool."