Option to close circuit
Vidalia allows that, and that's one thing we at Tails will be missing when we remove it. The main use case is debugging potentially buggy or malicious exit nodes. For example, you get an unexpected HTTPS or SSH warning, write down the info about your exit node, and close that circuit to get a fresh one and confirm your suspicions.
To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information