Lingua Latina aka WinLatin is, as far as I've found, the best free Latin drill program available. Although the page says it's unsupported, and doesn't work with Windows XP, I haven't had any problems with it (though I don't use all of its functionality). It's great for drilling on nouns, and pretty good for verbs (you have to be ready to drill all the moods and tenses, though, since there's no way to restrict it to, say, just the active forms). It stinks for vocabulary, since in order to get a right answer you have to match the entire entry, punctuation and all. E.g. for cogito, cogitare you have to type "think, ponder, consider, plan" or you it buzzes at you and won't let you continue. Still, what do you want for nothing? Rubber biscuit?
This page is meant to be a jumping-off point for examples of modern (aka 20th and 21st century) Latin verse as well as information about such things as scansion, poetic style, and anything else that seems related.
Latin Language Resources: Inflected Latin, Nouns
Just to double-check. Plus they bother to put in the vocative and locative.