Costa Rica is another central American country that will be a feasible option for almost all retirees with a pension, and which also offers an early retirement (no pension) option. The general perception is that Costa Rica has been discovered and is no longer the trendy choice. The upshot of that is that because of years of active interest from North Americans, the price level for housing that would please Americans is no longer what you could call inexpensive. Still, as anyone knows who has visited Costa Rica, this small country possesses many charms.
The two classes of entry for retirees are the pensionado and the rentista.
The pensionado requires proof of social security or pension producing an income of 600 USD per month. Thus, this type would more commonly be used by people of traditional retirement age.
The rentista option is for those without pensions. For this, you need to show a stable investment stream from a fixed investment of 1,000 per month, so in this case it sounds like you would need to tie up at least 200,000 USD depending on the interest rate. This might appeal to the younger retiree who can tie up that amount of capital.
Some links to check out:
http://www.costarica-embassy.org/consular/living/retirees.htm
http://www.costarica-embassy.org/consular/living/rentists.htm