Mobile data usage/allowance

[PikeyPriest]

I`m looking at getting an N95 on vodafone (so a 120mb data pack before it gets pricey). Is 120mb enough to last a month with moderate use? With no downloading, but checking a couple websites over a day? Or would it frequently be running out towards the end of a month? Are there easy ways to check your data usage?

I`m not sure whether to wait for the 8gb version on T-mobile, or just stick with vodafone.

Thanks for any help