Jessica Biel and Colin Farrell

The 30-year-old actress loved working with the reformed hellraiser on new sci-fi movie 'Total Recall,' Jessica - who is engaged to Justin Timberlake - believes people are drawn to Colin simply because he is excited about life, rather than because of his partying and womanizing reputation.

She said: "The thing about Colin is he is just so respectful and such a good guy. When you meet him the sparkle is more about having a curiosity of life, excited about the world and excited about what they're doing or travelling, it's that kind of sparkle.  It's that kind of magnetism that I feel he puts out there in the world, he's just cool to be around."

Meanwhile, Jessica is still caught up in Olympic fever even though the London 2012 Games ended last Sunday and revealed she would love to compete.

She explained to UK radio station Magic 105.4's Breakfast show: "Every fourth year that comes around, I'm watching those gymnasts and they're all 4ft 11in and I realize it was never going to be a reality. I'm like 5ft 7in, it was never going to happen, but in my mind I'm always thinking, 'But could I have done it? Could I be a diver? No they're all 5ft 4 in. Could I have been a pole-vaulter, or a long jumper? So I'm always putting myself in there thinking could I still do it."

Jessica has been in London to promote 'Total Recall' - a re-imagining of the cult 1990 film which starred Arnold Schwarzenegger.

The movie also features Kate Beckinsale, Bryan Cranston and Bill Nighy.