Since I often work remotely (coffices and stuff), I use 3G/4G modems with me to provide some connectivity while I'm out. Adding the VPN services in-between I need to know how much traffic is passing through my network, inbound and outbound.
So iftop was the easiest and lightest thing I found. It's in Fedora's repos (I believe Ubuntu's too) so a simple `yum install iftop` resolved the deps for me with everything.
To run that, a:
iftop -i wlan0
(or whatever your interface is) would start that monitor. The listening would probably require you to sudo before that.
Google started their new service called Google+ which is the newest addition to their web toolkit collection. After the fail of Buzz and Wave (I'm sincerely missing the last one) this one stands a chance to survive and definitely shake the Facebook market.
Few hours of clicking around I was happy with the light version of network - the standard minimalistic design (total lack of any design according to some users) and lightweight platform unlike Wave. The invitation procedure that we know since GMail works as well - plenty of mediocre users wanted them to be _in_ only for the being special case. However.
A great review on the subject is the comparison of Plus with Wave and Buzz. I'm hitting the +1 on that one.