Question: Im developing an application to print flight paths on a world map.

To do this i need a dataset to describe the latitude and longitude of various coastlines (and country borders if possible) of the world so I can plot them.

Is there anywhere on the web I can find this kind of data? (preferably free/cheap)

Thanks!

Answer: 
Check NOAA's [GSHHG](http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html) (Global Self-consistent, Hierarchical, High-resolution Geography Database).

The database is constantly being updated and maintained (latest update since Im answering this Q: July 1, 2013) 

GSHHG is:

> 
> a high-resolution geography data set amalgamated from two data bases
>  in the public domain: World Vector Shorelines (WVS) and CIA World Data
>  Bank II (WDBII). The former is our basis for shorelines while the
>  latter is the basis for lakes, although there are instances where
>  differences in coastline representations necessitated adding WDBII
>  islands to GSHHG. The WDBII source also provides all political borders
>  and rivers. GSHHG data have undergone extensive processing and should
>  be free of internal inconsistencies such as erratic points and
>  crossing segments. The shorelines are constructed entirely from
>  hierarchically arranged closed polygons
> 
> 
> 

The data are available in hdf4/3, ESRI Shapefile and binary formats.

<http://www.soest.hawaii.edu/pwessel/gshhg/index.html>
GSHHG is definitive your first choice, but depend on the scale you need take also a look at <http://www.naturalearthdata.com/>