The A-Team star is following in the footsteps of teen superstar Justin Bieber by calling on devotees to raise cash for Charity: Water by donating $29 (£19) to the fund in lieu of gifts. The organisation aims to provide clean and safe drinking water to people in developing parts of the world.

In a message to fans online, Biel also reaches out to TV viewers who enjoyed her turn in funnyman Jimmy Kimmel's post-Oscars "Humpilates" comedy sketch, which aired in the U.S. on Sunday (27Feb11).

She writes, "$5,000 builds a well that will serve 250 people with clean water. This year, I want to team up with all of you to celebrate my 29th birthday by raising $5,000 TODAY to build one clean water project.

"I am asking my friends, family, and Humpilates devotees to donate $29 to build a water well and provide clean, safe drinking water to a community in need."

And the actress' appeal has been given a big boost by her pop star boyfriend Justin Timberlake. In a post on his Twitter.com blog, he writes, "Jessica Biel donating her 29th for @charitywater. Let's build a clean water well today!"

Bieber's loyal following helped the birthday boy smash his target of $17,000 (£11,330) on Monday night (28Feb11), before he officially turned 17 on Tuesday (01Mar11).

But Biel's charity appeal hasn't stirred the same amount of interest among her fans - only 14 people had pledged donations to the cause by Thursday afternoon, raising $885 (£590).

The actress also raised funds for Charity: Water last year (10) by completing a hike to the summit of Mount Kilimanjaro with a group of celebrity pals.