ok these steps seem to speed up the process. and it works with only one adapter.
Preparation :
Download command-line tool dd from
http://www.chrysocome.net/dd and extract to a folder on your computer C:\dd-0.6beta3
Download the partition manager from
http://www.partition-tool.com/download.htm and install.
1. Flash WP7 with smaller sd-card mounted in your mobile device. (about 10 - 20 minutes)
2. make an image of your sd.
Open a Console
XP : Start -> Execute -> cmd.exe .
Win7 : Start -> Enter in Searchfield -> cmd.exe
change to the folder where dd was extracted to
mount the sd-card in an (usb) sd-adapter. the command is described in
http://www.chrysocome.net/dd "Read the entire USB memory device" BUT use at least bs=4M as block size if you use 1M it will take hours. (about 5 -10 mins)
you can try greater values as 4M as the usb2-standard allows up to 30M per second (see
http://www.everythingusb.com/usb2/faq.htm#4). 8M is optimum for me.
3. write image to bigger card. put bigger card in the (usb) sd-adapter and execute the following command. (about 5 -10 minutes)
4. use the partiotion manager to copy the wp7 partition to the unallocated space at the end of the bigger sd-card. make it NOT primary. ( 20 - 30 minutes)
5. delete the 200MB fat16 and the first wp7 partition. (few seconds)
6. create fat32 partition with the partition tool on the unallocated space . select it as primary. (few seconds)
credits to all uf us.
you can skip step one if you did an image once. so the whole process takes about an hour. also you can use the image-file as backup if you mess around with wp7 or ruin your card or something. just copy back the image on a new card.