That is such a nice thing to offer.
Regarding the tool, it's a fantastic idea, but see this idea on DC here about a very similar script idea called Axem, implemented by DC member Justice : http://www.donationc...ex.php?topic=15482.0
Still it's a good enough idea to be worthy of multiple implementations.
Now about the donating and "branding", here's how i think of it:
When a coder who hangs out on DC makes a cool program and shares it with the public, it benefits this site. People learn about the site through such things, and decide to become active members, or donate to the site after discovering it, or write about the program which leads people back to the site, etc.
In other words, from my perspective i don't think there is any reason for anyone to go so far as formally giving their code to DC or asking that people donate to DC directly for their software. It's just as helpful to the site if you make DC your home away from home -- and either don't worry about donations, or ask for people to donate directly to you if they appreciate your work.
When good active people are part of the DC family, we all benefit (and it leads to more people discovering us and donating).
In fact, I think if individual authors asked people to donate to DC instead of to them -- it gives a misleadingly low impression of that programmer's contribution to the site, because even though someone might not be compelled to donate purely for 1 particular program, it's the totality of the site that may inspire people to donate -- and so ever little piece makes a difference.
We're thrilled to have you as part of the site and making it a funner place to hang out by sharing your stuff. A link to DC forum from your software/readme would be great so that people who like your software stop by here to discuss it. Other than that, just have fun and make yourself at home.
Oh and keep your eye open for things like the NANY (New Apps for the New Year) event we have here - since it's great to have more people participating in that.