The Blue Skunk Seal of Approval

This year at NECC I was directly approached by lots o' product vendors who wanted my involvement with their product - to try it, to serve in an advisory capacity, to promote it in my talks or writing. I am flattered, more than a little surprised since I am small fish in the ed tech pond, and a little uncertain about how to handle such requests.
To the credit of at least a couple vendors, they took the time to attend my session on "Policies for the Social Web" and scout out my online offerings to make sure we were philosophically aligned. This saves time since I am not impressed by limiting technologies - overly ambitious filters, monitoring software, integrated learning systems, etc.
But I am excited about some social networking tools that operate in a "walled garden" environment. These products offer many of the same benefits and experiences of common Web2.0 tools, but security through limited access and monitoring is a part of the design. I believe Gaggle.Net is the prototype for this approach to offering students a "safe" means of communicating online.
What I am trying to do is figure out what my personal guidelines ought to be concerning endorsing or even mentioning commercial products on the blog or in my talks. These are what I've followed so far:
- I will not endorse or mention a product (at least without a heavy-duty disclaimer) which I don't have experience using in our district. This is important. While the product itself might look very cool, it's only through experience that one learns about little things like support, compatibility, bug fixes, situational customizations, and unintended consequences of use. (Yes, we use and like Gaggle.Net.)
- I will not accept any form of remuneration for reviewing or writing about a product. (Exception listed below.) This includes trips, gifts, cash, cars, call girls or dictatorships of small countries. Not that any of these things have actually been offered to me.
- I don't take paid advertising on my blog or website.
- I don't wear t-shirts, baseball caps, or underwear with corporate logos. (I do have a hip flask with the ALA logo on it, however.)
- I do write "blurbs" for books and/or products that I've actually read or used and liked.
- I try to keep my recommendations my personal recommendations - not the school district's.
I suppose there are other guidelines I should set for myself. That readers trust my objectivity is important to me.
Now there is one big caveat to all of this. If the price were right, I would probably say just about anything. I am thinking $100K would pay off the mortgage, allow me to fill up both family motor vehicles at the same time, and get the LWW that new garbage disposal she's been pining for. Cool.
There is an old joke about a man who approaches a woman in a bar and offers her a staggering amount of money if she will sleep with him. She accepts. Then the man offers her five dollars if she will sleep with him. The woman responds, "Just what kind of a woman do you think I am?" The man responds, "I think we both know that. We're just negotiating the price."
I suspect it's good for my professional reputation I work in education where the profit margin is so small that the temptations just aren't that tempting...
What needs to be added to my endorsement guidelines?