why don't you get a few friends together and go to a nightclub (that will allow 18+ in, assuming most of your friends are also that age). That way you will all have a great time and the only cost will be entrance to the nightclub and drinks (make sure you do drink sensibly, 18th birthday or not). Or go for a meal with a crowd of mates, speak with the restaurant about now to ensure you get a table booked and say what the occasion, they usually put balloons and possibly a cake on for you (or you could supply it and ask the restaurant to put it all up for you). Whatever you decide on.... have a great time and make sure it's something you'll remember (i might be over 40 now ~ only just ~ but still remember my big ones 18th, 21st, 30th and 40th). HAPPY 18TH BIRTHDAY...