The problem is, nobody knows what you mean by 'mini GPS'?
GPS mouse? Like ADAPT AD-800 GPS with Sirf III chip?
3.5" pna (personal navigation assistant)? Or 5" pna's like many
fabricated in China for say USD 100
pda or gsm cellphone with Windows Mobile on it
They all work perfect with TomTom, Sygic, Navigon, IGo8 etc
Please make your choise and be more specific with your question.