Hi guys
My DSL went down this morning and I needed internet to work. I searched for a config all over but couldn't find exactly what I wanted. After a bit I got mine working fine so I thought I'd post this to help anyone else out there.
I am using a Huawei E1750 on T-Mobile UK running FreeBSD 8.2 amd64. I'm guessing i386 would work the same.
Things to change for others may be device, authname, authkey and the APN which in my case is general.t-mobile.uk
The post which helped me the most was from Greg Lehey that I can't put up since I have not made 5 posts yet 
First thing to do of course is: 'kldload u3g' and then plug in the modem.
default:
set log local Phase Chat LCP IPCP CCP tun hdlc command
ident user-ppp VERSION
tmo:
set speed 921600
set device /dev/cuaU3.0
set timeout 0
set authname "t-mobile"
set authkey "tm"
set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \
\"\" \
AT OK-AT-OK \
AT+CFUN=1 OK-AT-OK \
AT+CMEE=2 OK-AT-OK \
AT+CGDCONT=1,\\\"IP\\\",\\\"general.t-mobile.uk\\\" OK \
AT+CGACT? OK-AT-OK \
AT+CGATT? OK \
AT+CGCLASS? OK \
AT+COPS? OK \
\\dATD*99# TIMEOUT 40 CONNECT"
set crtscts on
disable vjcomp
disable acfcomp
disable deflate
disable deflate24
disable pred1
disable protocomp
disable mppe
disable ipv6cp
disable lqr
disable echo
set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.255 0.0.0.0