The UN Jobs site is useful as a compendium of what postings are being opened where, but as an information system it is nigh on useless. There is no way to track what you have seen and what you haven't seen, and no way to tell precisely what is new between now and the last time you visited (the new postings page notwithstanding).
I've written a small screenscraper which pulls down all the postings and converts them to an rss file. I don't know about other feed readers, but liferea can read from a local file. There's a ton of dependencies like BeautifulSoup and PyRSS2Gen, but anyone with a little motivation should be able to get this working.
