Sometimes it's quite 'hard' to speak in front of a group of people (seminars, public discussion, etc) even when facing an interviewer of job seeking or for applying scholarship. There is, however an art to speaking in public like a pro....
According to David Meagher (author of It's Not Etiquette), in realliving, jan/feb 2008, there are some tips can be applied to speak confidently, as follows:
a. fall - back position; it means that you should not dominate the conversation, no matter how interesting you are. This is, particularly, important in a small group situation. When talking with someone more important, start the conversation formally, which means that do not try too smart or personal. Furthermore, if the speaking takes place in a number of people, find out in advance what kind of occasion it is and how it will be structured.
b. taking it to the next level; this would mean that you need to know your material really well. You know what you are going to say. You can improve your speaking by practising pausing so your words do not come out in rush. One thing you can also do is take a deep breathe, as this can make you calm down.
c. confidence tricks; there are some 'factors' that can support your speaking in public confidently; i.e. a). clothes, as comfortable and suitable clothes give you the best start possible; b). posture; fake confidence if you have to, relax your shoulder down and push back a little, keep your chin up, breathe slowly and talk 'tall'; c). smile, by making your whole face grin.
d. talk to anyone; when talking to anyone else, either in groups or one-to-one conversation, you should keep maintain eye contact, which shows your interest. Also, you need to listen (be attentative), as the more you listen and ask question the more others will find you interesting...
e. stance is important; open hand/arm gestures welcome people to ypur point of view.
f. last but not least; be sharp and succint deliveries is best.
So....have a practise and.... good luck... ;-)