"USB 3 + SATA 3 Combo card
I just got a CalDigit USB 3.0/Sata 3 (6Gb/s) card (two ports each).
(CalDigit FASTA-6GU3: USB 3.0 + eSATA 6Gb/s PCI Express card)
Works great in Lion. eSATA operation requires no drivers, but USB3 operation does require a driver install which they certify for OS 10.7. (see below for later driver update)
I'm running OS 10.7.5 with no problems. I haven't tested on 10.8 though.

(he later wrote)
I just checked their site and downloaded the latest driver - they are now showing OS X 10.8 support for USB 3, but I can't test that. (No 10.8 install.)
-Jim W."

As of 5PM Oct 4, 2012, the Caldigit drivers page "FASTA-6GU3" card section (farther down the page) driver D/L is listed (text) as "Driver v1.3.6 for Mac OS 10.5, 10.6 & 10.7" - but at the top of the D/L page OS X 10.8 is mentioned in the USB3 driver for the "CalDigit AV Drive". (That driver D/L link goes to a page titled "SuperSpeed USB 3.0 PCI Express Card (Desktop) / ExpressCard (NoteBook) driver" - Driver v1.3.8.)
I downloaded from both pages and both download the same filename (CalDigit-USB3-Driver.zip) that includes an OS X 10.8 driver v1.3.8, dated July 27th, 2012.
  

"About OS X Mountain Lion 10.8.2 Supplemental Update (26.65MB)
The OS X v10.8.2 Supplemental Update is recommended for all users running OS X Mountain Lion v10.8.2 and includes the following fixes:

• Resolves an issue that may cause DVD Player to unexpectedly quit
• Allows Safari to access secure sites when parental controls are enabled
• Addresses an issue that may prevent systems with more than 64 GB of RAM from starting up
• Resolves an issue that may cause certain Japanese characters to appear incorrectly in Mail

SHA1: ccd53770fd5beff7c457594599907d8a36e40807"

"About OS X Lion 10.7.5 Supplemental Update (2MB)
The OS X v10.7.5 Supplemental Update is recommended for all users running OS X Lion v10.7.5 and includes the following fixes:

• Resolves an issue that may cause Time Machine backups to take a very long time to complete
• Addresses an issue that prevents certain applications signed with a Developer ID from launching

The Supplemental Update is recommended if you installed OS X v10.7.5 Update (build 11G56).
It is not needed if you install the OS X v10.7.5 Update (build 11G63).

SHA 1: 644284dd913a207214c02a9e84945195d7b20c9a"

• Freeware VM VirtualBox v4.2.1 build for OS X 10.8.2 compatibility
• Canon Printer Drivers v2.10 for OS X
• Epson Printer Drivers v2.12 for OS X
• Lexmark Printer Driver v2.9 for OS X
• The "Lost" Steve Jobs Time Capsule
• Writer, former Apple employee Ken Segall reflects on Steve Jobs' legacy
    

(below 2 docs revised for Supplemental update)
• About the OS X Lion v10.7.5 Update
• About the Lion Server v10.7.5 Update
  
  
• Mac OS X: 64-bit kernel frequently asked questions
• Finding your Mac OS X version and build information
• Creating an iCloud account: Frequently Asked Questions
• iPhoto, Aperture: Changes to VAT when ordering books
• Mac 101: iCal (OS X Lion and earlier)
• OS X: Printer and scanner software available for download (ref: driver updates above)
  
  
• iTunes Store: Troubleshooting iTunes Match
• Archived - iTunes Ping: Frequently Asked Questions (RIP)
  
  
• iPhone: How to reset or change voicemail password
  
  
• GarageBand for iOS and Mac: Project compatibility
• GarageBand for iOS: Join regions unavailable
• GarageBand for iOS: Issues with songs created with newer version of app
• GarageBand for iOS: Audio may not switch outputs with Apogee Jam
• GarageBand for iOS 1.2: Optimizing Jam Session network connectivity
• GarageBand for iOS: Playing Touch Instruments produces unexpected results
• GarageBand for iOS: How to undo a recording on iPhone and iPod Touch
• GarageBand for iOS: Microphone not recognized with iPod touch (3rd gen)
• iMovie/GarageBand for iOS: Can't send HDMI audio w/Apple Digital AV Adapter
• GarageBand for iOS: Delay in recordings after turning off Airplay, Bluetooth, or HDMI output