All right; reference email & documents required off-line during travel uploaded onto to Evernote. Here is the workflow. Created off-line Notebook 'Budapest Off-line' on Evernote app on iPad. Emails retrieved in Spark iPad app --> Saved as PDF---> to Evernote 'Budapest off-line' Notebook. Immediate sync between all iDevices. Good to go :) Am not too sure whether I could've done similar using OneNote app. Does OneNote has the feature to create off-line Notebooks..?