There has been no recent official/confirmed Fukushima reactor updates, which is encouraging. Because they tend to jump fast to report when there are bad changes.
So... focusing on the measurements and official announcements - as this is the most objective and least panicked measure of the current situation.
@makiwi has also published a list of radiation monitors that she is watching, mostly the same as below.
Iwaki, Fukushima saw 3.84 microsievert high, has since come down. Probably a blip due to the smoke cloud passing.
At Ibaraki Tokai 2 monitor, the high reading has also been decreasing after the explosion blip. http://www.japc.co.jp/pis/tokai/trend2.htm
Ibaraki prefectural announcements, including radiation measurements: Japanese, English by Google Translate
At 8.30am, 8217 micro sieverts were measured by the main gate at Fukushima Nuclear Plant 1 (NHK)
The radiation level at the plant gate 9am was 11,930 micro sieverts, but dropped to 496.4 by 3pm. (Mr Edano's press conference a few hours ago, and TEPCOs measurement chard - PDF http://www.tepco.co.jp/cc/press/betu11_j/images/110315e.pdf)
RT @makiwi An amateur geiger counter in Hino, Tokyo shows a spike to about 90 CPM (about .9 microsievert) around 12:30PM on the 15th, now it's back down
Readings online: http://park18.wakwak.com/~weather/geiger_index.html
Note: the computer was restarted at 9:50am 17 March JST.
Gunma monitoring point spiked, but has since decreased again: http://www.pref.gunma.jp/05/e0900020.html
Yokohama monitor station: http://www.city.yokohama.lg.jp/kankyo/saigai
MEXT readings on the 16 March
Information releases from the Fukushima prefectural government, including results of water measurements. In Japanese, and translated to English.
Unofficial google map of unofficial and official monitoring stations and alerts
IAEA updates on the reactors: http://www.iaea.org/newscenter/news/tsunamiupdate01.html
TEPCOs press releases are notoriously slow and lacking in information: http://www.tepco.co.jp/en/press/corp-com/release/index-e.html and in Japanese: http://www.tepco.co.jp/tepconews/index-j.html
The most recent TEPCO measurement car update for the Fukushima 1 plant was at 1pm local time (JST), 16 March: (PDF in Japanese, Fukushima 1 measuring car update 1:10pm 16 March (in English from Google Translate): Google Translation of the PDF document)
TEPCOs March 16th press release on the status of Fukushima 1 and 2.
Japan's Nuclear and Industrial Safety press releases: http://www.nisa.meti.go.jp/english/index.html
Japan Atomic Industrial Forum reports: http://www.jaif.or.jp/english