[Bostonian]

For quant finance, by looking at recent papers on SSRN, arxiv (there is a quant finance section), by getting email updates from finance journals of their new papers (often the working papers can be found online), and by subscribing to some free newsletters from New Economic Papers http://nep.repec.org/ .

A caveat is that one can spend so much time keeping up-to-date that one's own research languishes.