Data APIs/feeds available as packages in R EDIT: The Web Technologies and Services CRAN task view contains a much more comprehensive list of data sources and APIs available in R.  You can submit a pull request on github if you wish to add a package to the task view.

I'm making a list of the various data feeds that are already hooked into R or that are easy to setup. Here's my initial list of packages, and I was wondering what else I'm missing.
I'm trying to limit this list to "real time" or "close to real time" data feeds/APIs, where the underlying data might change between downloads.  There's plenty of lists out there for static datasets, which only require one download.
This list is currently biased towards financial/time series data, and I could use some help expanding it into other domains.
Free Data:
Data Source -  Package
Google Finance historical data - quantmod
Google Finance balance sheets - quantmod
Yahoo Finance historical data - quantmod
Yahoo Finance historical data - tseries
Yahoo Finance current options chain - quantmod
Yahoo Finance historical analyst estimates - fImport
Yahoo Finance current key stats - fImport - seems to be broken
OANDA historic exchange rates/metal prices - quantmod
FRED historic macroeconomic indicators - quantmod
World Bank historic  macroeconomic indicators - WDI
Google Trends historic search volume data - RGoogleTrends
Google Docs - RGoogleDocs
Google Storage - RGoogleStorage
Twitter - twitteR
Zillow - Zillow
New York Times - RNYTimes
US Census 2000 - UScensus2000
infochimps - infochimps
datamarket - rdatamarket - requires free account
Factual.com - factualR
Geocode addresses - RDSTK
Map coordinates to political boundaries - RDSTK
Weather Underground - Roll your own
Google News - Roll your own
Earth Sciences netCDF Data - Roll your own
Climate Data - Roll your own
Public health data - Roll your own
OAI Harvester - Open Archives Initiative harvester
RAmazonS3 -  S3 Amazon storage server
Rflikr - Flikr api    
Requires a subscription:
Bloomberg - RBloomberg
LIM - LIM
Trades and Quotes from NYSE - RTAQ
Interactive Brokers - IBrokers 
 A: *

*Instructions for using R to download netCDF data can be found here, a common format used for storing Earth science data, e.g. as in marine geospatial data from OpenEarth or climate model driver and forecasts from UCAR

*rnpn (under development) enables you to get data from the National Phenology Network - a citizen science project to track the timing of plant green-up, flowering, and senescence. See the developer's blog post.

*-obsolete- RClimate provides tools to download and manipulate flat-file climate data (with tutorials, including here-

*Download historical finance data with tseries::get.hist.quote

*Michael Samuel's documents downloading public health data

*raster::getData provides access to climate variables via worldclim 
A: There's a project aimed at creating R packages with this objective (R interface to real-time APIs) called rOpenSci, which has 18 packages currently available or in development. Some (rnpn, rfishbase) are on your list already.  
Great list!  and full disclosure - I'm part of the rOpenSci project. 
A: *

*ONETr - efficient interaction with the O*NET™ API, offering occupational descriptor data from the U.S. Department of Labor.

