As analogika says, you could use either the free
PocketMac software from RIM which is due to get an update sooner than later (sarcasm) or the third party
Missing Sync for BlackBerry.
I don't know how it differs for the 9000 (I have a Pearl) but in order to get the BB powered by the Mac (USB) you have to install the Pocket SyncManager cause it includes a driver to make this possible.
The main thing you have to remember is -at least with the Pearl- you can't have Mass Storage activated and use PocketSync Manager at once.
I haven't used it for a while and that was under 10.4, but in order to send picts I used Bluetooth File Exchange (inside your Mac OS X Utilities folder) which is faster and easier than to deal with the aforementioned apps. Well, sort of easier…
- you firstly chose the file to be sent from the Mac to the BB
- then the device to receive the file (the BB smartphone obviously)
- again in the BB you have to choose the folder where you want the file to be saved
- next, press the BlackBerry menu button (the one with the BB logo) and choose "receive by BT" (please note on my phone it reads 'recibir mediante BT', given your location says Rep. Dominicana maybe it is the same for your friend)
- clic the Send button on the Mac
- odds are the Mac says something about an error, happens always to me but the file was sent flawlessly to the BlackBerry
The first time (and only the first time) you connect the BB and the Mac via Bluetooth, the Mac is going to ask for a password, which has nothing to do with any other password you had set up, you just have to write down the same password on the phone and then on the Mac.
Hope this helps.