urls are very useful.

if you go down the route of options 2 or 3, a related problem would be custom formats on cells. a simple example is something like conditional formatting: color cells red if the value is outside a pre-defined range, make bold if negative, make blue if field1 is less than field2, etc. lots of permutations are possible. i could also see a case where you have a 'status' field and you want to change formats based on the status of that record.