The Blumax GPS-4043 is a Bluetooth GPS Logger. Although it sizes is bigger than e.g. the wbt-201, it has some nice features (logging auf 130000 points, bluetooth, very fast positioning).
This device also works perfectly under Linux, using the program mtkbabel (see in universe-repository of ubuntu).
First you connect your device to your pc via bluetooth or usb. With bluetooth you have to scan for your bluetooth device (hcitool scan). Here you get something like this:
root@morphbook:/home/morphus/bin# hcitool scan
00:1C:88:10:AB:XX Blumax BT-GPS
Now you tell your PC to connect to that device:
rfcomm -i hci0 bind rfcomm0 00:1C:88:10:AB:XX
The following steps are the same for usb and bluetooth connection, use /dev/hci0 for bluetooth and /dev/ttyUSB0 for USB (see dmesg)
To get information about your device just type mtkbabel -p /dev/hci0
To get the logged data, just type mtkbabel -p /dev/hci0 -f filetowrite -t -w
Then you should find three files in your directory, first the binarydata in filetowrite.bin, then the waypoints you've marked in filetowrite_wpt.gpx and third filetowrite_trk.gpx with the whole track.
Now you can use gpsbabel to do anything you like with these files.