SSRS 2005 - Email report on execution to dynamic list with dynamic parameters = no schedule

Hi,
   I have a need to display on screen AND email a pdf report to email addresses specified at run time, executing the report with a parameter specified by the user. I have looked into data driven subscriptions, but it seems this is based on scheduling. Unfortunately for the majority of the project I will only have access to SQL 2005 Standard Edition (Production system is Enterprise), so I cannot investigate thoroughly.

So, is this possible using data driven subscriptions? Scenario is:

1. User enters parameter used for query, as well as email addresses.
2. Report is generated and displayed on screen.
3. Report is emailed to addresses specified by user.

Any tips on how to get this working?

Thanks

Mark Smith