MemoryLifter has free downloads in subject areas such as Languages, Arts, and Social, Applied and Natural Sciences. This free flashcard program is PC-based. The cards can be downloaded and printed out for use or they are a great way to practice using an interactive whiteboard. A couple of my favorites were the US States and Capitals and Musical Intervals.
Once you've installed the free program and downloaded a set of flashcards, you will be able to edit the cards to fit your needs. A card collector feature and an audiobook generator are included. The card collector allows you to generate cards using drag and drop or copy and paste. Many more modules can be purchased from $2.95 to $75.95. Sharing your own flashcard set is easy to do with just a few clicks. The LearnLift staff will review the content and then post is so everyone can have free access to it. They will also consider purchasing your module if you would prefer to sell it to them because it is a specialized unit or has a lot of time invested in its creation. Either way, it is a great way to share knowledge.