I am off to pick my lad up from his work soon and at that place there are some nice lobworms last time I collected some they all rotted on me so whats the best way to keep them for a few days?

Put them in a bucket of soil, not to wet or they'll go soggy.
Tigger.

give em some bits of boiled potato to eat, and make sure they have air

Make sure the soil/medium is PH neutral. Lobworms don't adjust to variations in acidity. You may be best going for large dendrobes. They can tolerate changes in acidity without much fuss and they can grow to sizes equal to that of Lobworms if you follow Jeepsters instructions.
You can mix powdered potato (Mr.Mash or Smash) through the medium and the worms will happily pile on weight.

For a few - or even several - days they'll be very happy in damp shredded newspaper in a baitbox or groundbait bucket. Keep them cool + dark, no probs.

Avoid peat-based compost, IMO.

In a cool dark place, lobs should stay fresh in wet shredded newspaper for several weeks.

Remember to keep it damp, and don't put in any damaged worms or the good ones won't last long either.

For more information see: http://www.anglersnet.co.uk/authors/leon11.htm

Tight Lines - leon

They'll be very happy in damp shredded newspaper in a clean baitbox or groundbait bucket.

I used to work for a mole killer and he kept gallons of lob worms (Yes gallons!) in dustbin sized barrels of soil. We collected most of the soil from where the worms were gathered. Don't have the soil too wet. I think he kept layers of newspaper, or bits of carpet on top and gave them a sprinkle of water every now and again.

Damp shredded newspaper in the bottom of a baitbox with damp moss on top of that. This keeps them fresh on the hottest of days provided they are kept in the shade.