There's one thing you can do right now that will help the Dems win in November. The main event has already begun, even before tonight when John W McCain solidified his victory the initial shots had already been fired. Right now McBush is at his weakest - his money is relatively low, he potentially has campaign spending limits looming over him, and he has to go running to Mr. 20% to beg for money and support. Our candidates are too busy running with the primary to turn their attention to the old Republicant Rerun, so the task of defining him falls to our old friends the DNC. So, unless you have the ability to bend HIllary's ear and the influence to convince her to drop out to end the primary tomorrow, the best thing you can do to help Democratic chances in November is donate to the DNC. They're the ones who will be doing the yeoman's work of campaigning against McFlightsuit 2.0 (it comes with an actual military record this time!). They also may get stuck with a bill of running a do-over in FL and MI that the media seems to be salivating about these days, so they can use every contribution you can spare.
Even better, if you get a Democracy Bond the DNC will have a steady stream of resources to fight all the way through the election. I confess that part of the reason I signed up for one a couple of months ago was on the chance that Hillary was going to win the nomination I wanted a vehicle of voicing my displeasure if she dumped Howard Dean and went back the Terry McCaullif way - even if it was a small contribution it is something they would notice if it happened en masse.
Have you maxed out your donation to either or both Clinton and Obama? Then may I suggest that donating to the DNC may be just the avenue for contributing more you've been looking for. I know it doesn't have the flair of the newfangled 527's, especially since the banning of "soft money" contributions, but the DNC does vital work in getting out the vote and exposing George Bush John McCain for the hypocrite he is on lobbyists.
So, please, let the DNC take some of that filthy filthy lucre off your hands, because for every point McCain gains in the polls makes 35 year olds who live with their parents wet their beds in fear... Or is it the other way around?
Looking for other options? May I suggest Votevets.org - they've been doing a fantastic job of making sure tha McCain is held accountable for his war mongering brown nosing of Bush and the insane Republicant base.