So you're planning your first meeting. Congratulations. You made it this far, now let's wrap it up and make a successfull Event!
First of all, avoid any long talks in the first Meeting. Give them a good introduction of what Google Tech is capable and try to find Speakers that could talk about the big spectrum of APIs and Apps. I don't know if you have staff from Google that is attending your meeting, maybe Stephanie and Van or the other Googlers could help you to get into contact.
You can find potential Speakers here: http://code.google.com/team
Hand out Namebadges for every registered Participant and if you could lay hand on some good Badges with Lanyard do it. It looks way more professional than handwritten Badges, alltough it's not the most important part of the evening.
Print the Name and maybe Twitternick on both Sides or use sticky Notes or Lables (http://global.dymo.com/enAU/Segments/Professional_Solutions.html for Example)
Also, you will have some people showing up that are not on the list, so bring a few blank Badges and Pens.
After doing the short keynote, if you don't have more than 30/40 Attendees, maybe do a short introduction round where everyone stands up one after another and tells his name and three tags describing them.
Like: my name is Nils Hitze, Nerd, Dad, Blogger.
It's always nice to have a name for a face and not a room full of nameless people you might not meet again.
If you have some swag (t-Shirts, pens, stickers, books) to give out and more attendees, make a quiz about Google-related questions, like "what Color is the Android Robot", "how many Android Capable Phones are out there", "what is Scumm standing for" and so on.
Raffling Swag is a good way to wake up the people after a talk and to get some action into the evening.
Always use swag to support the most active members of your community. You should save the larger items for organizers, speakers, active participants (during e.g. hackathon), and prizes, and be more liberal with the smaller items. Being a Leader is about Modesty not Greed!
Don't fill up the complete timeframe with Sessions. I personally could live without Full Frontal TechTalks, i love CodeDemos and Socializing.
So let there be enough free time before/during/after event where everyone can get to know each other, talk about cool stuff they build, etc.
Talking/Listening makes thirsty/hungry.
Get some Sponsors to buy you a Case of Beer and some Coke.
If you don't find a Sponsor, organize some yourself and take a Dollar the Bottle (slightly more than it cost, just to get you the Money back)
Most important of all it is to document the whole event. Do Photos, Videos (or even better - live streaming) and twee a lot about the meeting. Find yourself a good hashtag like #gtugsyd and print it to a big Poster so everyone sees it and promote the use of it in all social networks, so you can find the results later.
Encourage your Attendees to do the same. You are only one man, find someone to help you. Maybe one of your friends has a better camera, ask him for lending it to you or ask him to come over so you don't have to take the photos all by ourself.
Setup a page in a Wiki or install something like Dokuwiki to document the Sessions and to link to the Slides and Presenters.
http://silberkind.de/dokuwiki/gtugmuc shows you what i mean, although it's in German.
http://www.ijeyanthan.com/blog/?p=67 has a summary of a successful summer camp held by GTUG Madurai
After the Meeting write a Review as soon as possible and spread this out and post it at the GTUG Manager List so we can see how awesome it was :)