Add two columns "total" and "registration date" on the participant page

1) when you manage events, it's nice to be able to filter per registration date (to see who's new)
I would be great to have that directly on the participant list:

/civicrm/event/search?q=civicrm/event/search&force=1&crmSID=1_d

2) For paid events, it would be great on the top/ instead of the Fee Level to have the total (and display the sum at the bottom of the table)

X+

P.S. Lobo, what's the Civicrm version I should choose to minimise your work ? I do tend to use the current stable one 2.0, but you seem to affect it to 2.1, what would you like me to choose ?