Is there a Ubuntu keyboard shortcut to type a "ƒ" (latin hook f)?
On a Mac, I used to be able to do ⌥ Opt+f and it worked everywhere.
There are two main ways of doing this, it's genearlly down to personal preference which you choose:
EDIT: Option 2 will work in most cases, but may not work in some places, including certain terminals.
Ctrl+Shift+U is the command sequence for inserting any unicode character, and 0192 is the character code for "LATIN SMALL LETTER F WITH HOOK"