My brother and I are considering using an apartment-finder service in London, but the cancellation policy is very restrictive. Therefore, we would welcome recommendations for proven travel insurance sources that are reasonably priced and afford broad coverage (to perhaps even include volcano related flight delays/cancellations if available). Our thanks, and we rely heavily on Rick Steves' London guidebooks. Bob
Try QuoteWright.com - they are a travel insurance comparison web site where you can compare plans side-by-side.
I have used TravelGuard a couple of times, and had to use it. The previously mentioned insuremytrip.com is the best place to start. highly recommended by Clark Howard (a thrifty consumer radio person, who also is a big Rick Steves Fan).
Buy it within 15 days of your first trip non-refundable cost, and you're also covered for any pre-existing medical conditions. When I used it, they even helped with some Dr information and had a nurse on call.
I never do a trip without it now.
Travel Guard (Platinum)