Put the person on supervised release, put an ancle monitor on the person and put the person to community work, until they become a net benefit to society.
Other solutions may apply, but at least the above is better than three strikes.
That brings to mind an interesting question. Why should prison time be proportional to the crimes committed?
If the purpose of prison is rehabilitation, then shouldn't the time be however long it takes to rehabilitate the prisoner? There might be some correlation between that and the crimes committed, but I would expect that to be a weak correlation. There will be many people who are easy to rehabilitate whose first crime was very serious and many people hard to rehabilitate whose first crime was relatively minor.
Society only obeys the rule of law as long as there is some consensus that the law is fair and just. Basic fairness demands that breaking a rule should result in a punishment.
The punishment is only fair if it is proportional to the offense. Therefore prison time should be proportional to the crimes committed.
While punishment for crime certainly appeals to our instincts, should we not consider more "humane", and possibly more effective crime reduction measures (rehabilitation over punishment)?
The original discussion was about alternatives to three strikes (which explicitly both of us oppose). Notice the lack of value judgement of rehabilitation vs. punishment.
Secondly we were discussing the concept of proportionality. I expressed the rationality of society's need for proportional punishment. Notice how I did not present my personal views regarding rehabilitation vs. punishment.
So far we have only established that I believe that the punishment for a crime should have an upper bound which is proportional to the offense.
Now, whether the purpose of the prison system should be punitive or rehabilitative is another discussion.