Re: No Mic input just speaker &...
yeah Bj, my old powerbook had a mic pre on it and I used it quite a bit for skype if nothing else. When they dropped them, it wasn't a major, but I had to get a headset with a USB mic pre/ headphone socket on it and you know, it was another piece of kit you had to remember to take with you.... or another thing to get broken!
Jim, pre amps come in all shapes, flavours and wallet lightening varieties!
First off, if you have access to a mixer or PA, or already own something of such a nature, then they will have mic pres on them. For a quick solution, you could take a line output feed from the mixer and, with the right cable, plug that in to the 3.5mm line input on your computer.
If you don't have a mixer or existing mic pre of any description, then you could look at getting a USB or firewire sound card to get one.
Something such as the M-Audio solo or fast track are popular choices for people not wanting to shell out too much cash but get decent results. They can be found here.
Depending on your budget and requirements they can go to esoteric prices, however, something else that might help us would be what mic you plan to use with it? Dynamic? Condenser (something that will probably need powering)?
What do you plan on recording? Vocals? Guitars? What do you plan on doing with the recordings?