This is an interesting PDF:
Emerging Technologies from Memory Palaces to Spacing Algorithms: Approaches to Second-language Vocabulary Learning
While many studies have analyzed the results of these projects, there has been less attention paid to programs which are dedicated, not to incidental vocabulary learning through reading, but to the intentional study of sets of vocabulary. This is an area of SLA (second language acquisition) that has been out of fashion, as the sense of rote learning it evokes is out of step with the model of communicative language learning, fostering as it does the idea of language as something mechanical and fixed. Yet, in this area, some interesting and innovative work is being done which goes well beyond simplistic electronic flash cards. In fact, integrating sophisticated tools for dedicated vocabulary study into on-line environments for language learning offers an important resource for serious, long-term language learning.
…One approach which moves in the opposite direction calls for individual learners to create a highly individualized system for vocabulary retention. This involves linking in one’s mind new vocabulary to something concrete and familiar to the learner, such as items in a room in one’s home. The familiar locale provides a memory hook which can be used to retrieve linked items by perusing mentally the trajectory through that physical space.
The article also mentions the VUE (Visual Understanding Environment) and CmapTools, which appear to be mind mapping or (“concept mapping”) programs.
If you are interested in language learning, check it out.
See also, Mnemotechnics in Second Language Learning.