Vodafone has three rolling contract options, but none of them include Wi-Fi access. There's no daily rate option.
1GB per month: Like O2's option, 1GB per month from Vodafone costs £10 per month. Without Wi-Fi included, though, it looks a bit pricey by comparison.
3GB per month: Again this falls into line with its competitors, costing £15 per month.
5GB per month: Unbelievably this tariff costs £25 per month, which is the same as Orange's 10GB, Wi-Fi included option.
Though Vodafone's 3G network is highly regarded, its iPad plans look very uncompetitive. They're okay if its 3G coverage is good in your area, but we can't see many people flocking its way.
3 has the most basic iPad options, with just the two tariffs available. Both are pure 3G, so don't include any Wi-Fi.
1GB per month: At £7.50 per month this plan undercuts both O2 and Vodafone, while matching Orange's weekly tariff.
10GB per month: This £15 per month option looks like excellent value if you're not fussed about Wi-Fi and live in area with good coverage. Orange's 10GB per month tariff costs £10 more.
If you live or work in an area with good coverage for the 3 network, its options - particularly the 10GB per month plan - look like excellent value.