Hi,
You can buy slightly sweet and salted air popped popcorn which is low salt and low sugar from Blockbusters, this is ok to have and is yummy (i only like real sweet popcorn but this is lovely!). It is low GI as well so should keep you fuller for longer.
You can also dry roast chickpeas, they are crunchy and yummy. Or have some nuts or seeds, sunflower seeds are the nicest, they have a nutty taste.
70% cocoa or more dark choc, have 1 large square a day if you like (i was told this by my nutritionist). I used to hate dark choc but now i love it. Try different brands they are all slighty different.
Make your own "cereal" bars...i found a great recipe and have made them they are scrummy...
http://www.veggiemealplans.com/index.php?option=com_content&view=article&id=836:my-husbands-favorite-breakfast-bar&catid=1:recipes&Itemid=67#yvComment
Houmous with a small wholemeal pitta bread.
Plain yoghurt with berries and a little honey.
xx