Transfering databases from one development machine to another.
http://adam.heroku.com/past/2009/2/11/taps_for_easy_database_transfers/
Those two solutions can be easily combined to transfer mysql database from one development machine to another (no more nasty dump emailing/sending/sharing etc.)
On first machine:
taps server mysql://db_user:db_pass@localhost/database_name online_user online_pass -p 5000proxylocal 5000
Last command will pop out an address (like http://tz87.t.proxylocal.com/ or similar)
And second machine (to obtain sqlite database):
taps pull sqlite://development.sqlite3 http://online_user:online_pass@tz87.t.proxylocal.com
How cool is that?