Using many of the creative ideas on this site, we used the Lego Brick invitation idea and used name tags to place on each lego to reveal each detail of the party. Then I used Lemonade Cylinder containers as the envelope" and place a rhyme about placing the bricks together--this is not a trick--to share in the fun at Lego Imagination Station Brookside 1241 (our address) and the rest of the information had to be assembled by the child/adult invited!  This was a hit with all the kids and parents--I included a parent only brick--wrapped in paper--that detailed the other children invited for carpooling purposes-- For favors I used the Lego outlet on the lego site and bought LEgo racecars for 2.00$!!! That was much better than supplying candy and knickknacks that accumulate in drawers!!  I also asked Friends with older children if they wanted to donate some legos to the imagination station so each child could make a creation to take home---their generosity enabled me to have a Lego party for my five year old---- We had a great time and the boys loved the games and playful interaction making ships guns etc. Thanks for all of your terrific help!"