You got a mac? Congrats. :) I hope you will like using it. (What kind of setup did you get?)
Just click, and continuing holding down the button - drag it to your desktop. (In most cases you of course have to displace the browser window slightly so the desktop becomes visible.
With that said I don't personally care for the one button mouses. (It's about the only thing I don't think they got right.) I use right-click for contextual menues for almost everything I do.
Kensington have some really great trackballs and mouses. I use a three button StudioMouse Graphite plus an Expert Mouse Pro trackball (four buttons plus scroll wheel and 6 additional programmable buttons) plugged into my old G4. (I don't actually recommend my particular setup since I find the driver (MouseWorks) does not let me configure them individually... ^_^ It's not a problem for me since I want them basically the same.)
Anyhow. You can get almost any mouse or other input device you want and it will work perfectly without any fuss. (I know never say never, but I've had only good experiences so far.) Some driver might have to be used for accessing special functions. (This is usually not a problem but some product developers just don't understand that mac users are an important group in the graphics business.)
Logitechs MX1000 looks pretty cool but I never actually tried it. Just about any mouse around should do. (Just not a sucky MS mouse :D (Microsoft is evil...) jk)
Ok time to stop rambling. My kid just woke up so it's time for our newest sports activity: Spreading food in as large an area of the dining room as possible. ^_^
Thanks, actually I figured that out a few seconds after I posted this but forgot to say so :-). I know I could replace the mouse but I am going to give it a while and see if I can get used to it... call it a case of style over substance.
Me and both of my boys can and often do navigate through the Macs without ever touching the mouse, I drilled them on the keyboard shortcuts until they now often use the shortcuts without even thinking about it.