How to add Service to Finder Toolbar
Solution 1:
You can create an application doing exactly this using ScriptEditor.app and then add it to Finder Toolbar.
First place this line inside your ~/.bash_profile
file:
alias cdf="eval \"cd \\\"\\\`osascript -e 'tell app \\\\\\\"Finder\\\\\\\" to return the POSIX path of (target of window 1 as alias)'\\\`\\\"\""
This will change the active directory to the one of the topmost Finder window.
Then create an application in ScriptEditor.app like:
tell application "Terminal"
do script "cdf"
activate
end tell
Save this as an application and add it to the Toolbar with ⌘ CMD + Drag.