Well 13-16 for me though I think that's not as accurate as it could be.

Basically this is the trend for me for the last two days:
2.5G, 1 jabber connection(this also sends me mail notification through the Jabber Mail Component, and links me through to MSN, ICQ through transports), 1 sip connection, data plan widget slow refresh, calendar widget, conversations widget, fmtx widget, 2-4h xmms2 music playing, maybe a ssh connection from time to time, a conversation or two, maybe a 1 minute phone call, 30 minutes of hex-a-hop playing.

Trying now more or less the same but with 3G only connection will see how it goes.