I compiled the Mobileread
Full List (with only .IMP ebooks) here at mobileread.com as of today (Sept 3, 2008) into ebook format.
Try and see if you can download it to your reader from here, If not, just download it to your computer and then upload it to your reader from there! then open the ebook on the reader and select a title therein.
This will surf to the upload thread with description and link to the actual .imp. Select the .imp link and it will be downloaded directly into your reader.
Now the fun begins, you have to find it under some category. Usually the 'General Interest' category is used so look there first.
This works great for me, as long as I strike out that part above, when using my EBW1150!
Have fun and give us some feedback on how well this works for you (state your reader and firmware if you experience problems)!
As usual, the ebook ending with _1200.imp is for the REB1200; the other .imp for the EBW1150.