Here are some randomly selected joke topics beginning with the letter 'I'
Income tax
You know you're having a bad day when - Your income tax refund check bounces.
In laws
The kindest thing I can say about my wife
is that her in-laws are a lot nicer than mine.
In charge
A HUSBAND: The man who knows he is in charge, and has his wife's permission to say so.
Income
The average income of the modern teenager is about 2 a.m.
Incompetence
Work is accomplished by those employees who
have not yet reached their level of incompetence.