Dianne Feinstein is circulating a petition asking President Bush to make federal funding available for research on more embryonic stem cell lines. For those of you who don't remember his policy, Bush decided that federal funds could be used to do research on any stem cell lines available as of the day he announced his policy. He claimed at the time that there were over 60 such lines (to the amazement of people I know in the field); in fact, only a handful were usable at that time, and even now only 21 lines are available.
Why does this matter, you might ask? Well: cell lines are not all alike. Some are more robust than others, some have weaknesses where others have strengths, and so forth. In order either to do research or to develop therapies, it's important to have a line whose individual characteristics are suited to your needs. (It's like hiring a person for a complicated job: the bigger your applicant pool, the more likely you are to find a really good candidate.) Besides, scientific advances since Bush announced his policy mean that stem cell lines derived now are safer than any of the lines on which federally funded research can be done, but scientists can't use federal funds to do research with these safer lines. (This will become important when researchers start trying to develop therapies: if Bush's policy is still in effect, federally funded research will be required to use the earlier, less safe stem cell lines, and any therapies that result will expose patients to unnecessary risks.)
Feinstein's petition is a good one. You can sign it here: http://feinstein.senate.gov/stemcell.html