In case you missed any of these catchy tunes last week, it's not too late to boogie down. Grab your headphones, CD player, iPod, speakers, guitar, cowbell, whatever you need -- it's time for the M&A Mix Tape.

"Don't Cha" by the Pussycat Dolls featuring IntercontinentalExchange
On Thursday, IntercontinentalExchange (NYSE:ICE) hit CBOT Holdings (NYSE:BOT) with the line "Don't cha wish your bidder was hot like me?" Despite the cool "ICE" calling card, ICE is nothing if not hot. The stock is up nearly 250% since the beginning of 2006, and the company managed to double revenue and nearly double its net income margin in 2006. And now it is a bidder for CBOT.

CBOT is the holding company for the Chicago Board of Trade, Chicago's 159-year-old options and futures exchange. CBOT shareholders had been getting ready to vote on a proposed merger with fellow Chicago futures exchange Chicago Mercantile Exchange (NYSE:CME). For now, CBOT seems to be staying on track with its current plans, though traders seem to be betting on ICE shaking things up and have pushed shares of CBOT up past the CME bid. ICE's offer is roughly an 11% premium to the outstanding bid by CME.

As my fellow Fool Tom Taulli said, watching what transpires from here should be good fun as ICE puts on the full-court press, CME and CBOT decide how to respond, and as-yet-uninvolved players like NYSE and NYMEX determine whether to jump into the fray.

Morgan Stanley is working as the financial advisor for ICE, and Lazard Freres has been the financial advisor to CBOT in its proposed merger with CME.

"Come Together" by The Beatles featuring Cisco Systems
Rallying behind the buzzword of "unified communications," Rule MakerCisco Systems (NASDAQ:CSCO) is helping customers come together, and hopes that swallowing WebEx (NASDAQ:WEBX) will allow it to grab a much larger share of the market. WebEx provides on-demand products for Web conferencing applications such as "webinars," sales presentations, and online training.

WebEx is a dominant player in the conferencing applications market, with a 33% market share, according to research firm IDC. According to another research firm, Frost & Sullivan, the Web-based collaboration services market is expected to grow at a 30% annual rate over the next four years and reach $2.6 billion by 2010.

Fellow Fool Tim Beyers noted that there are some worrisome aspects to the deal, including the price Cisco is paying. In the long view, though, he also points out that this acquisition will give Cisco another foothold in the unified communications market it has in its crosshairs.

WebEx consulted Goldman Sachs (NYSE:GS) for a fairness opinion on the deal.

"Cupid's Chokehold" by Gym Class Heroes featuring Caremark
The battle for control of Caremark Rx (NYSE:CMX) looks like it's finally over. After a three-month bidding war, it appears national drugstore chain CVS (NYSE:CVS) will take home the prize, while Express Scripts (NASDAQ:ESRX) will go home empty-handed (save the bills from its lawyers). Express Scripts made it clear that it would like to continue the process and wanted more time to conduct diligence, but Caremark was not interested.

Despite vocal opposition from the huge California pension fund CalPERS, both CVS and Caremark shareholders voted in support of the transaction late last week. Express Scripts had offered a higher price for Caremark, but shareholders were wary of the legal hurdles ahead for the proposed combination. The marriage with CVS had already been given the A-OK by regulators.

The merger will give CVS, which derives 70% of its revenue from its pharmacy business, a much stronger position in pharmacy benefits management (PBM), as well as augmenting the company's bargaining position with drug companies. Increased traffic to CVS pharmacies should also have a positive impact on CVS' non-pharmacy business.

JPMorgan and UBS worked with Caremark on the transaction, and CVS tapped Evercore and Lehman Brothers.

Liner notes
Dollar General (NYSE:DG), the low-priced retailer which sells 30% of its merchandise for $1 or less, agreed to be taken private by KKR for $7.3 billion, including $380 million of net debt. Fellow Fool Timothy Otte pointed out that these types of retail take-outs are the flavor of the week because the public markets just don't have the patience necessary to stick with struggling retailers through a turnaround.

In health-care news, UnitedHealth (NYSE:UNH) announced an all-cash deal to take out health-care services company Sierra Health Services (NYSE:SIE). The deal is seen as a bid by UnitedHealth to put its foot down in the rapidly growing Nevada market -- and more specifically in Las Vegas, where Sierra is based. UnitedHealth claims that the acquisition will be immediately accretive to the tune of $0.04 per share without consideration of any synergies between the two companies.

And rounding things out, Microsoft (NASDAQ:MSFT) -- good ol' Mr. Softy -- announced the acquisition of voice-recognition specialist Tellme Networks. Though Microsoft did not officially announce the financial terms of the transaction, rumors had the acquisition price in the neighborhood of $800 million. Tom Taulli sees the acquisition as strengthening Microsoft's position in the burgeoning area of mobile search.

That's it for this album, but be sure to keep tuned in to The Motley Fool for more tunes from the M&A front.

Microsoft and UnitedHealth Group are Motley Fool Inside Value recommendations. UnitedHealth Group is also a Stock Advisor recommendation. NYSE Group is a Rule Breakers recommendation. JPMorgan Chase is an Income Investor pick. Try any one of our investing services free for 30 days.

Fool contributor Matt Koppenheffer is currently ranked 4,511 out of 24,614 Fools participating in The Motley Fool's CAPS service, and he encourages everyone to get heard. He owns shares of Goldman Sachs and UnitedHealth, but does not own shares of any of the other companies mentioned. The Fool's disclosure policy always delivers those block rockin' beats.