HDMI (High-Definition Multimedia Interface) is mainly for Video/Audio transmission. Your new i7 27" iMac does not have a HDMI interface, but it does have a mini-display port interface. I believe on the 27" iMacs, you can use the mini-display port as monitor IN port.

Usually, the Mini-display port is used to feed video data OUT to an external monitor. Apple made available the option of using your iMac as a big monitor with the mini-display port.

However, the EVO has a regular-old USB port also. You can sync un-DRMed music/videos from your mac using DoubleTwist.

 

I can't really think of a situation you would want to connect the EVO to your iMac with HDMI considering basically everything on your EVO is from your computer.

 

Are you confusing HDMI and USB?

USB (which your mac certainly has) is used to sync data to and from your Evo, which is what you sound like you are wanting to do. The Evo will come with the appropriate USB cable and you'll be good to go.

HDMI is used primarily to hook your Evo up to a TV, just as a way to display things on it on a bigger screen. This cable is an extra that you have to buy through Sprint (most likely for now).

 

I'm a long time mac user and am currently using a late 2008 model Macbook with Snow Leopard. Android phones do not require much interaction with your computer.

Contacts
All of your contacts go through GMail, so I would recommend setting up that account and getting all of your contacts sync'd before you get your Evo.

Video Out
Your iMac if I'm not mistaken only has a displayport output, no type of input, so you won't be able to plug your Evo into your iMac monitor without some 3rd party type solution (I assume one exists, but I have no idea). Obviously if you have an HD tv you can plug into that.

Apps
All of your apps don't sync through anything like iTunes, they are all done over the cloud, so no worries about Mac compatibility there.

Music
If you are planning on putting music on your Evo I would suggest downloading doubletwist. It can sync your itunes library/playlists to your Evo without any problems. Or, you can just go for the drag and drop method. Plug your Evo into your Mac, select Mount as Disk Drive and your phone's sd card will appear on your mac just like any usb drive would. Simply drag and drop files to it.

Ringtones
Here's the easiest way to set up your ringtones. On your phones sd card, create a folder called "media", inside of media, create a folder called "audio", inside of audio, create three folders "ringtones", "alarms", and "notifications". Then just put your corresponding files into these folders. Now when you go into your Evo settings and select a ringtone/alarm/notification your sounds will be there. There are other ways of doing this, namely using an app like Rings Extended which will let you pick any audio off of your sd card for ringtones/notifications/alarms, but I prefer the neatness of the method I just described.


So in short, your experience on a mac will be no problem.