wgPicasa has now three versions available.
The lite version is Free of costs, the Pro version is 5 euros for 2.5 version and 9 euro for joomla 3 version only.
Both can be used in Joomla using php5.

Feature wgPicasa
Lite
wgPicasa PRO 2.5 wgPicasa
Lite 3x
wgPicasa
PRO 3x
Joomla version Joomla 1,5 & joomla 2.5 Joomla 1,5 & joomla 2.5 Joomla 3x only Joomla 3x only
Choose thumbnail size Checkmark_25x25 Checkmark_25x25 Checkmark_25x25  Checkmark_25x25
Config maximum thumbnails per row Checkmark_25x25 Checkmark_25x25 Checkmark_25x25  Checkmark_25x25
Config maximum thumbnails per page Checkmark_25x25 Checkmark_25x25 Checkmark_25x25 Checkmark_25x25
Multiple web albums on one site Checkmark_25x25 Checkmark_25x25 Checkmark_25x25  Checkmark_25x25
Albums available within articles Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Showing Hidden/Protected albums Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Making different configuration of your album which can be used in menu or article Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Make selections of albums in config Remove-icon Remove-icon Remove-icon  Checkmark_25x25
Select showing username Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Select showing text; number of albums Remove-icon Checkmark_25x25  Remove-icon Checkmark_25x25
Select showing photo title Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Select showing photo description Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Styling text and thubmnails by css Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Workable with standard SEF Remove-icon Checkmark_25x25 Remove-icon  Checkmark_25x25
Title of Albums in Popup Remove-icon Remove-icon Remove-icon  Checkmark_25x25
  Download Download   Download