SORRY BUT I AM ONLY ACCEPTING RESPONSES FROM RESEARCHERS WITH AT LEAST
A 4 STAR RATING
THANKS
QUESTION:
I want to connect to the internet using my laptop running Win XP
connected to my mobile phone which runs on the UK vodafone network.

I want advice on the best way to go about this in the UK

Ideally want to connect at GPRS speed or higher though i don't want to
use 3G (connections to weak in my area).

I already have a sim card which is GPRS enabled, so ideally i want to
use that and not have to buy a new simcard package/rental

Also, my phone is capable of connecting to my laptop via infrared or
data cable and I think I should be able to use the phone effectively
as it has a built in modem

I am confused though because Vodafone sells several options for connecting 
and none of them seem to suggest using your existing phone - is this
because it can't be done?
or are they just looking to sell me something i don't need?

My phone is a samsung SGH P400 and ideally I want someone to give me
detailed instructions on how to connect to the internet using my
phone, including advice about what ISP I can use.

My home ISP provides broadband access via ADSL to my house. I don't
have a dial-up PSTN provider.
(I was wondering if I at worst I can dial up a PSTN provider using my
mobile at 9600bps at least to prove the point. But haven't managed to
succeed in that because PSTN ISP's don't seem to allow mobile numbers
to dial in - a CLI issue i think)

Anyhow, this is what Vodafone offer as far as I am aware:

a) a card using 3G I DO NOT WANT THAT
OR
b) Vodafone Mobile Connect PC Card
£143.95 for GPRS and you have to have line rental charge monthly

If i can't use my phone direct and i really need a card then my
preferred alternative would be

c) Option GPRS/GSM PC Card (Vodafone Branded) sim-free use existing sim card
£79.95 which i can buy from expansys
and i assume i can use my existing SIM card in it which is GPRS enabled

I am aware that there are per mb charges on data downloads

I would also be interested in alternative providers if they are
cheaper and provide a similar level of coverage (I live and travel
outside the big cities in the UK although mainly in the South East of
England).

NOTE: Orange and T  mobile do not work well enough near me. So the
only other alternative would be O2 if i have to use a different
network.

SUMMARY of my questions
a) how to connect to the internet at GPRS speed using my phone and who
is the ISP i dial
b) if a) is not possible then can i use my existing sim with a vodafone card
and who is the ISP
c) if a and b not poss then i will do the vodafone package with sim
but any comments on costs compared to O2 would be interesting

3G is not an acceptable solution

i am not four stared but i have too much experiece to connet inter net
through mobile becausei use it

 ifu wanto connet your laptop with mobile and and want to use GPRS ,
then folloeing thing are must required

1) sim card which should ne enabled with GPRS
2) mobile must have function of GPRS (all mobile dont have function of
  GPRS,check if your mobile have function of gprs )
3)all seting of gprs must be done in mobile phone (u can get these
settings from your service provider company ,in your case
vodaphone,these are some type of ip and user name and passwords only
your service provider can tell u this
4)install the pc sute software of your mobile and install the modam
software of your mobile which u can get form the websight of your
mobile phone
5)after all these things connect to inter net by computer not by
mobile to use net on computer by using sofware of your mobile modem

then enjoy  , these thing seems difficult but its too much easy ,
remember setting canm be taken only from your service provider

thanks for your comment bilalarshad-ga

My phone and card are GPRS (as i already have said)

i don't want to have to hunt through websites to find the exact
settings , i want the researcher to do that

and give me more specific info