I've just created a few commands for simplifying the usage of svn:ignore property of Subversion from command line. You can download, and see the sources on the project page.

The usage is simple, typing:

svn-ignore-add path/to/file-to-ignore

will append to the current svn:ignore property of "path/to" the string "file-to-ignore".

The project was written in Bash with TDD.
The xUnit framework used is an modified version of shunit2 that I hacked sometime ago for the trash-cli project.