I just renewed my travel insurance from World Nomads (no affiliate relationship) for another six months. Although I’ve never had to make a claim they seem to provide solid service at a reasonable price and are recommended by Lonely Planet.
If you decide to ever buy insurance from World Nomads you should be aware that different durations have surprisingly different monthly rates. I ran the full estimates for one to twelve month travel insurance for a 29 year old American male from World Nomads and found again, just like last time I did this, that six months is an optimal period.
There’s no penalty for creating a new contract while still on the road so I’ve again opted for six months. Run the numbers yourself — the savings is too big to pass up for a long term traveller.