Here's an interesting paper (http://arxiv.org/abs/0803.4015v1) whose authors describe the use of gravitationally lensed quasars to measure the value of the Hubble constant. Their technique is independent of Sandage, HKP, and WMAP. The value they measure for Ho is:

"Our estimate of H0 agrees with the concordance value: non-parametric modeling of the lensing galaxy predicts H0 = 67 +13−10 km s−1 Mpc−1, while the Single Isothermal Sphere model yields H0 = 63 +7−3 km s−1 Mpc−1(68% confidence level)."

In other words, their analysis puts Ho in between the Sandage value and the HKP value.

I like the gist of the Sandage et al paper that Jerry mentioned, as it pin-points uncertainties/limitations to Cepheid-based measurements of Ho. You have to first admit there is a problem before you can take steps to improve your situation. However, the fact that several different methods (including the SZ effect) are now giving us roughly similar values for Ho (60-80) shows that there has been undeniable progress in this area of observational astronomy and we seem to be at least closing in on the "true value" of Ho. Now, what would really be nice, will be if gravitational waves are detected and then used to (i) most importantly, independently confirm that the Universe is expanding, and (ii) measure Ho to a couple percent precision. Gravitational waves, unlike light, are not effected by as many contaminating factors (extinction, reddening, etc).

Caution! Before everyone gets too excited about my last point, note what a scientist involved in one of the gravitational wave experiments recently said about gravitational wave detection (from http://www.wired.com/science/space/n...tional_waves):

"And now LIGO scientists have begun searching their data for this gravitational wave signature. If scientists continue to detect nothing, however, Einstein's theories may well need modifying.

"If we don't see anything in four years," Foffa said, "then it will be the time to start questioning."