I do this in a fashion?
I have a couple of Sony digital dictaphone things. One cheapo one, and one more expensive one. (The cheapo one was for use in my truck.. and is hammered).
These are quite small things, which slip into a shirt pocket with ease.
Both units I have can use vox (voice activated), so you don't have keep pressing buttons. However, I found in a moving vehicle, the road noise can trip the mic.
To get around this, you can use a small clip on mic (like they use for mobile hands free kits), and set the vox to its lowest setting.
I actually find pushing the button easy though, and its a single touch and your off.
Each recording is stored with various details, like length, date, time etc.
The more expensive one I have has a memory card to store the recordings
The real clever part with the more expensive one, is that it has a socket on the bottom, which using the supplied lead plugs into a USB port on a computer.
The supplied software which came with it, then allows you to save /copy /backup all your recordings. (This works both ways, so you can transfer files from PC to recorder.. The recorder also plays MP3s)
The whole copy thing with the computer just syncs as soon as it plugged in, dead simple to use.
I carry the cheapo one around everywhere.. its my "notepad". If I need to write a number down, take an address, ect.. especially when driving it is brilliant.
I even use separate folders on it for work and leisure
Might not be what you want though !?