As far as small USB hosts, an Android phone with a USB OTG cable would be a pretty nice way to connect to something like this and copy files back and forth. I d

As far as small USB hosts, an Android phone with a USB OTG cable would be a pretty nice way to connect to something like this and copy files back and forth. I don't think they're very vulnerable to most of the usual potential nastiness of a malicious USB device. But no matter what sort of device you're using, it's pretty far from anything an actual spy might use. Any actual spy would want something discrete enough that you could be watched, videotaped, and photographed from multiple angles while making or picking up the drop, and even with endless analysis of the recordings, still have the security service not know that anything happened. Some of Tom Clancy's books are pretty decent on realistic spy tradecraft, even if they're dicey on other subjects.