Best pre-paid plan for travelers that spend a lot of time OUS?

[ianshakil]

I'm interested in purchasing one of these low cost prepaid plans to go with my Nexus 4. I travel a lot, and I'm often OUS for several months at a time. During these periods, I do not wish to re-up my prepaid accounts. Unfortunately, it appears that Straight Talk deactivates your SIM after 1 month. Simple Mobile deactivates your SIM after 90 days. Are there any other good solutions?

-Ian