When I used Eleanor Burns method with strips, I loved the ease of sewing without precutting each block...BUT...the blocks didn't turn out right. The logs were askew. I found out that this was caused by not precutting each log, so each length was not exact.
These log cabin rulers by Marti Michell (Nifty Notions) come in three sizes and make perfect blocks:
http://www.frommarti.com/mm5/merchan...gory_Code=R-LC