Retail and OEM shipments of removable flash cards expected to more than double to 243 mln units by 2011 from 118 mln in 2007. US Shipments of USB flash drives are expected to rise to 64 mln units in 2011, up from 37 mln in 2007. Worldwide shipments of removable flash storage cards and USB Flash drives will reach 1.5 bln and 308 mln respectively by 2011, iSuppli says.