A reader recently tipped me to Newzpile, a service by Kailash Nadh (Commentful; boastMachine) which relaunched just over a week ago in its third version (with everything re-thought; including the concept). Newzpile is a service where you type in tags or keywords, and it essentially spits out in real time the latest buzz or 'memes' around it from a range of sources.
Newzpile searches several places, from Yahoo! News to Digg to Flickr, although except for showing the results in an orderly fashion doesn't do much with them. It's also worth noting they give away a handy ticker for meme-enthusiasts and bloggers alike. The main reason I think anyone would use Newzpile (and my reason for profiling it) is because of its pure speed and simplicity — it's quite nice to have a service without the loading times and which just works.
The concept, although is extraordinarily similar to what TagJag is (and has been) doing — in a way, it's been lifted — and for some reason its interface also greatly reminds me of Popurls, another service I love for across-Web 2.0-meme-tracking.
There's no doubt that this space is sustaining a bit of growth, although I can't help but question the niche audience of these services: Geeks? Web 2.0 nerds? Early adopters? Bloggers? 'Stumble-uponers'? Surely, if this is all that comes to mind then this sort of stuff might not ever get to the masses — although it is admittedly quite handy for us geeks.