How to make Bitcoin-Qt or other client run off of a flash drive (Mac) I work in an office with lots of computers, and I am on a different workstation every day. Is there a bitcoin client I can keep on a FireWire/USB drive?

Bitcoin-Qt on Mac leaves all the files in the home directory - the block chain, the wallet, etc. Someone else is going to be using this computer tomorrow! I want to keep all those files, and even the application itself, on a portable drive.
Somebody posted a portable client, but I don't trust them, so I'll show you how to make your own.
Windows guide

Download the windows .zip from bitcoin.org

Unpack it. Go into that directory.

Make a file called launch.txt
Put this in it:
 start bitcoin-qt.exe -datadir=data


Rename it to launch.bat

Make a folder called data


It should look like this. Double-click launch.bat to start it. If files show up in the data folder you made, then you've done things correctly.
Macintosh guide
Download the Mac .dmg from bitcoin.org
Find the Bitcoin-Qt.app file, and copy it to to your flash drive.
Go to Launchpad, type in 'terminal'. Hit enter.
When the terminal comes up, type:
cd /path/to/flash/drive
mkdir data
cd Bitcoin-Qt.app/Content/MacOS
nano start.sh; chmod +x start.sh

Type in:
#!/bin/bash
dir1=$(cd &quot;$(dirname &quot;$0&quot;)&quot;; pwd)
dir=`echo $dir1 | sed 's/&quot;/\\&quot;/g' | tr -d '\n'`
data=&quot;$dir/../../data&quot;
&quot;$dir&quot;/bitcoin -datadir=&quot;$data&quot;

Now hit Ctrl-O, enter, Ctrl-X. You should be back at the terminal.
cd ..
nano Info.plist

Find the lines that look like this:
    &lt;key&gt;CFBundleExecutable&lt;/key&gt;
    &lt;string&gt;Bitcoin-Qt&lt;/string&gt;

Change it to:
    &lt;key&gt;CFBundleExecutable&lt;/key&gt;
    &lt;string&gt;start.sh&lt;/string&gt;

Now hit Ctrl-O, enter, Ctrl-X. You should be back at the terminal. Now we just need to give it a better name.
cd ../..
mv Bitcoin-Qt.app BitcoinPortable.app

Try running your BitcoinPortable.app. If you see files show up in the data directory next to it, then you've done things correctly!
Thanks to Pygy for the script
Note: I don't have a Mac, so this is untested.