Our plan is to go web 2.0 with this product, adding comments, article rating and building a community around the job of environmental management. I would love to see examples of this in other industries.
You don't. You redefine the problem. It's fire and motion from the big corporations side. See Joel's classic post here: http://www.joelonsoftware.com/articles/fog0000000339.html
When you look throught the clutter it is obvious that the large companies don't really need all those shiny features - they need better software. And what they have now sucks.
Take a totally different perspective, start attacking IBM for being too expensive, attack Lotus notes for their horrible user interface that takes employees years to learn. Write about how crazy it is to have an email client that is XML compliant. Set your own agenda. People will notice.
Look at Basecamp and Highrise and you'll see plenty of proof that this strategy is totally viable.
The other huge advantage a web-based app can offer over the traditional corporate apps, which those apps can't easily compete with once you start rolling, is that there's no hardware + license fees, only a monthly service subscription. You take the headache and high initial cost out of it, and you open these types of apps to a much wider class of businesses too.
Microsoft does this against IBM. Most Enterprise Business Units at Microsoft starts at the small-medium size business and work their way up toward IBM's level.
In contrast to the B2C market for web 2.0 apps where consumers expect everything to be free, once you break into the corporate markets there are customers willing to pay big bucks for your product.
The primary problem is selling into this market. There are a lot of technicalities and the customers don't decide to buy after your first meeting. It requires a prolonged effort. If you get a programmer and a savvy salesman with experience in selling to large companies together I think there might be gold at the end of the rainbow though.