Kant is a very simple python script for choosing graphically an ant task.
Simply run the script with your ant file as arguments, and the task listed in the file (or in the files linked as imports) will be displayed. Just choose one, and it will run the task !
This script uses kdialog to build the dialog box.
For more conveniance, you can create a new file association in konqueror for file with the pattern "build.xml" to this script. Then, just click and run a task.