Speaking of going broke on cabs - we got to SFO last night, and hadn't asked any of our kids to come pick us up - thought we'd just cab the 35 miles home. We got our luggage loaded into a tiny cab (one suitcase jammed into the front seat) and the driver pointed out that the fare would be nearly $200 with tip!!! We UNLOADED, schlepped around a 1/2 mile walk/drag with our luggage up to the second level and caught a SuperShuttle instead - ended up being the last drop-off nearly 2 hours later, but only $49.
We walked around as much as was practical over the four days, but there were a lot of cab fares involved - we probably spent $150 over the four days, plus $85 for car service to the airport yesterday. But as cold as it was, and as out of shape that we are, I think it was worth it. But I did enjoy most of the walking we did do.