This Geeklet uses the BOM Text output to display Location, Temperature and Forecast.
The URL for this data is: ftp://ftp2.bom.gov.au/anon/gen/fwo/IDA00100.dat
Change the word from Sydney to your capital city to get it's forecast.
Remove the section | grep Sydney | to get all capital city forecasts
e.g
curl --silent ftp://ftp2.bom.gov.au/anon/gen/fwo/IDA00100.dat | awk 'BEGIN { FS = "#" } ; { print "\n"$1,"\nTemp: "$7"C","\nForecast: "$8 }'