I created such news aggregator a while ago and I use it every day. (time / facebook likes) + mark bubbles that are in my hashtags.

Check it at: http://daaaily.com

This is really great. Love the design and interactions. How can I contact you?

Send me email at jernej.pregelj88@gmail.com

Don't miss to filter by phrase. Here are some of the HN classics visualized:

http://social.gnod.com/hn?search=balsamiq

http://social.gnod.com/hn?search=whatsapp

http://social.gnod.com/hn?search=pinboard.in

http://social.gnod.com/hn?search=tarsnap

I have been reading HN like this for about a week now. I'm planning to add some more data sources over the next weeks.