Hello
We are spending a week in Gran Canaria from Apr 17 and then going on to Tenerif for the second week - what is best way to get from this island to the other on any day of the week? We are staying in the south on both islands.
Regards
bazzer

Most of the inter-island flights are to/from Tenerife North airport - so that should be a consideration if you are staying in the south if Tenerife.

Check out the following for ferries:
http://www.fredolsen.es/PublicSite/FredOlsenExpress/

and for flights;
http://www.bintercanarias.com/