Tips for getting DD to sit on the toilet

[spook14]

My DD is two and a half and after ups and downs she's fairly well potty trained BUT won't use the toilet, which means I have to carry a rucksack about with me all the time with her potty in it!
Any tips to encourage her to even try to sit on the toilet?

Has she got a girl friend who's slightly older than her? Our dd decided she wanted to use the loo when she saw her friend doing it - then she wanted to be a big girl like X.
In our small outside loo I've also installed one of those kitschy see through seats with fish etc on it - when dd has mates over they queue up to use that loo!

Is it just a problem when you ar eout ? If so you could try a Tommee Tippee Toodle-loo seat to give her abit of security. ds used a toilet insert seat at home until he was 4ish but dd never needed one. 2 1/2 is quite young to use it instead of a potty (some will though) but I never took a potty around with me for either of mine so it was just not an option.