In fact, consider yourself lucky if you can connect at 28.8 more than half the time. Besides data functions, most modems double as a fax. Some models will let you carry on a conversation with the person whose modem you have called, though for most people this feature isn't worth much. Watch for real cheap prices on the latter type in the next few months. There's a continuing debate over whether internal modems, which plug into a slot inside the PC, are better than external modems, which plug into a serial port in the back of the machine.
Internal models are cheaper, take up no space and are marginally more convenient.
External models give you more information about what's going on via their front control lights. About my only contribution to the debate is that I prefer external models because you can usually shut them off and recover when an Internet connection hangs. You tend to need to restart the PC with internal models.