Though i had found this tool long time back, it came about pretty handy while using it recently.
Get it from jUploadr
Just untar the package and run
jupload from the installation folder. This launches a simple UI which allows you to drag and drop photos to it. Just add a flickr account and authorize juploadr to upload. You can add individual tags and descriptions to each of your photos. Its purely written in Java and hence portable across platforms.
Update: On ubuntu, there are other flickr upload tools too. Notably good ones are postr and dfo for gnome and kflickr for KDE.
To install simply type sudo apt-get install postr or sudo apt-get install kflickr at the terminal.