This is ideal if you are travelling and the kids want data access or you for business. Sometimes the wifi is not free in hotels or you can't get it in the rooms.
I was looking for a data sim to take abroad where they are not included in 3's at home plan and found this one.
It runs on the 3 network and you can get 1gb of data for £4.94 or 5gb for £14.94. There is also 10gb at £19.79
This price is for one month.
It is done on a per month plan but you can cancel as soon as you want.
If you commit to 3 months in advance they will double your allowance..
Also free 100mb on top to use:
All MobiData plans, including our FREE TRIAL, can be used anywhere within our network (see our coverage) and ALL paid plans come with 100MB of FREE international data*