First, absolutely phenomenal plugin! I've searched for months for a simple website to do what this plugin does, and the only one that comes close has a censor (BOOO!). This plugin is exactly what I've wanted for years--a quick, easy database to store my favorite quotes.
This may have been covered before, but I've found an easy solution for the export/import feature that's promised. For those who know how to view their WordPress database in MySQL (there's a plugin for this), all one needs to do is "dump" their 'quotes-collection' table to an XML file. Presto, easy-to-read backup of all your quotes.
If you're trying to import after a fresh installation, or import across a multisite network, you can append or overwrite this XML file to the quotes-collection table for whatever blog needs it.
I'm sure it wouldn't take much work to write a quick plugin to do all this from the settings menu, and I might get on it myself one of these days. In any case, this is one plugin that I will never deactivate!