I think not. But that's what a dearth of good products has led us to. So don't feel bad for breaking security rules. Here are some of the ways you are coping with your online identity crisis. It is completely impossible to use the same username at every site, even if you wanted to do so.
Digital certificates have tremendous potential.
Advocates of single sign-on should seriously consider getting behind this technology and building the demand that will cause businesses to accommodate them and build better functionality for them. I'll second that. Single sign-on would be the ideal solution for the scenario you described. However, I also agree with you that neither Microsoft's nor Novell's SSO products are ready for prime time on that grand of a scale. Now, I just have to find that lockbox.