Here's a look at monthly house payments (including mortgage and property tax) compared to incomes and rents:
Loads of exposition can be found in the full writeup at voiceofsandiego.org.
I'm not sure if people are hopping over to the Voice article so I'm going to include here a bit discussing the pros and cons of using monthly payments as a valuation indicator.
On the con side:
It is pretty clear that for most of the history displayed on the charts, the payment-to-income and payment-to-rent ratios hewed pretty closely to mortgage rates themselves. Typically, the monthly payment ratios would move up when rates were moving up and down when rates were moving down. It wasn't until the recent housing bubble, when the payment ratios shot up while rates dropped and then languished at generational lows, that this relationship broke down.
But the recent bubble is an abberation in which home prices rose not due to low rates but to an extended period of incredibly reckless mortgage lending. Looking back beyond this risky-lending-induced bubble, there just isn't much historical data to suggest that homes should necessarily be more expensive when mortgage rates are low and less expensive when rates are high.
The point can be further illustrated by comparing the recent bubble peak to the early 1980s, when double-digit mortgage rates prevailed. If monthly payments are a good valuation metric, then these charts suggest that the overvaluation of the recent bubble was not nearly as large as that seen in the early 1980s. This is ridiculous, of course. The recently burst bubble absolutely blew away prior booms in terms of magnitude, as a quick glance at the bubble aftermath depicted in this long-term foreclosure graph easily demonstrates.
On the pro side (this is reminiscent of a point made by pigg ltokuda earlier in the year):
While payments aren't a good valuation metric by themselves, however, they do have an influence. Monthly payments are a crucial element of the rent-or-buy calculation and will thus affect the level of demand coming from renters or investors jumping into the market. This phenomenon can perhaps be seen in the fairly consistent payment-to-rent "floor" in the second chart above.
All in all, given everything that's going on foreclosure/economy-wise and the sketchiness of using monthly payments as a valuation measure, I don't see these graphs as providing much indication either that the bottom is at hand or that homes are a particularly good "value" here.