I\'m looking for a drop in solution for caching large-ish amounts of data.
related questions but for different languages:
Disclaimer - I am about to point you at a product that I am involved in.
I'm still working on the web site side of things, so there is not a lot of info, but Serial Killer would be a good fit for this. I have examples that use .Net serialization (can supply examples), so writing a persistent map cache for .Net serializable objects would be trivial.
Enough shameless self promotion - if interested, use the contact link on the website.