Sainsbury's have removed their bags from the packing areas at the checkouts, M&S are charging for their bags and other supermarkets are following suit to encourage us to supply our own and cut the number of bags that end up in landfill.

I think it's a great idea but I'm struggling with the basic bit - remembering to take the bags out with me. It's enough trying not to forget my shopping list or what I've gone out for, let alone remembering to pack a cotton shopper or a bag for life!

Twice last week I've had to juggle packets of biscuits, bananas and a French stick back to the car from the M&S petrol station in Long Lane/Uxbridge Road after refusing to buy another plastic bag (I only went in to pay for petrol so didn't take the bags from the glove box with me).

I also forgot my cotton shoppers last week when I went to Uxbridge, so I did my shopping in various shops, refused plastic bags and just kept adding my purchases to the flimsy bag from the first shop.

By the time I was almost home, the bottom was falling out of the bag thanks to all the '3 for 2' credit crunch offers in Boots!

When I do remember to take bags with me to the supermarket, I either end up with too many or not enough. But at last I've found the solution and I'm pleased to say it's a very clever invention by a couple of mums.

The innovative Footprint Bag is an extremely clever 'bag within a bag' system. It has eight black reusable and stylish bags made from super tough parachute material within one compact pack that can easily fit inside your handbag. Each bag folds up and fits neatly inside a little pouch and, best of all, there's a handy trolley coin attached too.

A trolley coin is another great invention that Iown but can never lay my hands on when

Ineed it! At least this way everything you need is in one place.

The Footprint Bag is so easy to use and I get envious glances every time I use them. The checkout staff and other shoppers always want to know where I got them from and I guarantee that one of the big supermarket chains will be snapping up this brilliant design very soon!

They are only available on the internet at the moment and are priced £19.50, including free post and packing.

Initially I thought this was quite a lot to pay but, as the checkout lady pointed out to me just today, that's less than £2 per bag and they are really worth it. She said she thought they were worth much more!

I've only used my Footprint Bag three times but was so impressed I've already bought two more as presents for family. [25cf] Find out more at www.footprintbag.com, including an offer for the rest of October only, with the Footprint Bag costing just £15.60.

Cathy's recommended event:TICKETS are now on sale for the Family Open Weekend, an annual event at the London Transport Museum's depot in Acton.

There are two days of special family events that are not to be missed if anyone in the family is likely to enjoy exploring more than 70 road and rail vehicles from the past, present and future. There will be special trips on a miniature railway that has steam and electric engines and trips on full-size heritage vehicles.

There are art workshops for children from age five, badge making for ages three and above, storytelling sessions and lots of hands-on activities.

For older age groups there are displays by professional and amateur modellers of working layouts, which cover all modes of travel in London, from Underground trains and trams to cycling and walking.

On top of all that are the museum's collections of vehicles, signs, photographs, posters, drawings, uniforms and architectural material.

The open days are Saturday, November 1 and Sunday, November 2. Opening hours are 11am to 5pm. Acton Depot is at 118-120 Gunnersbury Lane, Acton, London, W3 8BQ. The nearest Tube station is Acton Town (District and Piccadilly lines).

Tickets cost £10 for adults, £8 for seniors, £6.50 for concessions - there's no charge for under-16s and Freedom Pass holders. Call 020 7565 7298 to book now.