This is a tip only for dropbox users. The latest experimental build has this new feature ‘Pause Syncing’ which lets you pause or disable the active sync temporarily between your dropbox account folders and your local folder.
You might have already figured it out that this an extremely useful solution when you are using or editing the files, documents in from you dropbox local directory, where it starts to sync the temporary and garbage files unnecessarily.
Also if an ongoing dropbox sync is slowing down your video chat, voice call etc. you can simply choose to Pause Syncing (Right Click on the dropbox tray icon and select Pause Syncing) which will disable dropbox sync till you click "Resume Syncing".