Edit: As Steven Van de Craen points out, you can use the Properties collection on the Root folder for the List. Neat, didn’t think of that.
I like property bags in things. Sure, they’re open to abuse, but they give an easy way of storing a little extra data, and as a developer, I find that very useful.
For those of you who are wondering what a property bag is, well, it’s a collection on a object where a programmer can just store stuff. E.g.
SPWeb site = properties.Feature.Parent as SPWeb;
site.Properties["Kumquat"] = "True";
Now, clearly the SPWeb object in SharePoint’s API doesn’t have a property called Kumquat; we’re defining a new one, and storing a string. In fact, string objects is all you can store.
Anyway, SPListItems and SPWeb both have property bags, but SPList and SPSite do not. Which is a little annoying, as I want to store some data at the list level, dammit. And I hadn’t realised this ommission until now…
Thoughts on Steven’s point – it’s a good one, and using the root folder would work. Naturally, this means that you’re storing the properties in the SPFolder object, but each list should have one of those, I think. It’s a bit of a pain as, if you’re using the Web Services then I’m sure that getting that root folder will take another call – but as I’ve not validated that the properties are available via the web services, then that might be a moot point anyway.