Yamaha Pocketrak C24 by ShelLuser
The Pocketrak C24, though dated, is still a recorder which should be taken quite seriously. Its small size and light weight make this device very easy to carry with you wherever you go, all it needs is one AAA sized battery. And even though its size is small, its features most certainly are not.
The 2Gb internal storage is plenty to work with, but if you're going to use it more extensively then getting an extra memory card is most likely the better idea. Even though the recorder can automatically compress your material for you in MP3 format. But compression is obviously not always a good idea if you're out collecting samples which you plan to use in your own material.
It also comes with several options for connecting external hardware. Using a separate microphone or a pair of headphones is not a problem. And if you recorded a piece of material then you can listen it right back thanks to the internal speaker.
What I especially like about the C24, apart from its small size, is its rich feature set. Its high pass filter for example can be the ideal solution to filter out noises such as wind or rumbles. The 5 band equalizer and limiter can be perfect when you're trying to actually record existing material (though I never used it for this myself). The metronome and tuner are perfect for the musicians amongst us, one of the reasons why I consider this to be a sound engineers swiss army knife.
Finally; copying any recorded material to your computer couldn't be easier. Just slide out the USB connector using the slider at the back, then simply plug it into an USB slot. Either on your computer itself or an USB hub. Windows and Mac. will recognize the device as an USB mass storage device, which makes getting your material as easy as copying any other file using your operating systems file manager.
In fact: the mass storage aspect can also be a perfect way to quickly copy any DAW presets which you might have made "on the road", so that you can carry them with you until you're ready to further use them. This idea is also used by Yamaha itself it seems, because the Pocketrak manual is actually stored on the device itself in PDF format.
Concluding: if you're looking for a not too expensive field recorder while you're also concerned about size then this could be a very good alternative for your needs.