Our exciting Summer bikini competition is winding down, and tomorrow morning we'll unveil the two finalists! The races are fierce and you still have until midnight to vote for who you think deserves the title of Hottest Bikini Body of 2009. You only have two choices to make, so take a few seconds out of your day to fill out the bracket and you'll be automatically entered for a chance to win that iPhone!

Round four of our Summer Bikini Bracket ended last night and now we're down to the final four ladies in the contest. Jennifer Aniston and Jessica Alba are going head-to-head, while Bar Refaeli and Cindy Crawford are matched up in the battle of the swimsuit models. What's even more interesting is that in our top four we have two 20-somethings up against two amazing looking 40-year-old women. Voting in these pairs will be open until Monday at midnight, so make sure to log in and complete your bracket - and you'll be entered to win an iPhone! Official rules are here.

The exciting competition for hottest bikini body of 2009 is heating up as the fourth round ends tonight! Before the polls close at midnight, make sure to fill out your bracket and vote for all your favorites. Remember there's a chance to win an iPhone, so there's no time to waste - check out the official rules here. Click through for an update on who's currently in the lead.

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The second round of our hottest bikini bodies of 2009 competition ends tonight, so make sure to cast your votes before we head into the third bracket. Time is running out for these matchups - Jessica Simpson lags behind Reese Witherspoon, while Miranda Kerr has a good lead on Leighton Meester. There's still a chance to change the tides and help your favorites make it to the next round - log in, complete your bracket, and be entered to win an iPhone!

On Monday, we kicked off the 2009 PopSugar Bikini Body Bracket to narrow down 64 insanely hot celebrity ladies in swimsuits throughout the month of July and crown one winner. Virtually impossible, I know.

For the first two days of the bracket we watched you all vote and the closest margins were Reese Witherspoon vs. Sheryl Crow and Audrina Patridge vs. Katy Perry - those are some tough matchups. We also weren't surprised to see Pop favorites like Jennifer Aniston, Britney Spears and Rihanna on their way easily to round two.

This morning our friends over at Sports Illustrated Hot Clicks sent over their readers and whoa, just like that everything changed! I thought it would be interesting to take a look at how our predominately female audience was voting versus how the male influx changed the tides. Remember, the voting on round one ends on Saturday at midnight so there's still time to vote here and of course, when you finish any round you are entered to win an iPhone!

To see how the men voted vs. how the women voted just read more.

• Nicole Richie vs. Paris Hilton Our readers were all about Nicole, but after a few hours of testosterone-influenced voting, Paris Hilton has the lead.
• Britney Spears vs. Heidi Montag Turns out, the guys aren't as turned off by Heidi as some of you all are. She's still trailing Brit by a bit, but Mrs. Pratt is closing in.
• Kristen Bell vs. Sienna Miller The two blond beauties make a close matchup, but men can't seem to get enough of cute Kristen Bell who has taken the lead over Sienna.
• Reese Witherspoon vs. Sheryl Crow Reese scored the number 2 spot on the PopSugar 100, but when the SI readers came to town they were all impressed with the crooner's rock hard abs as she scooted ahead of Reese.
• Rihanna vs. Hayden Panettiere: Number one seed Rihanna was off to a quick lead, but barely-legal Hayden caught the eyes of the guys.
• Favorites All Around... Leighton Meester, Bar Refaeli, Gisele Bundchen and Jennifer Aniston are looking like shoo-ins right into the next round of the bikini bracket!

So what do you think about these generalized findings - interesting or predictable?