I use Chikka.com for more than 2 years now. yep its really cheap way to send messages from Phil to UK (Php2.50) and vice versa (free).

When i was in the Phil, i also had a yahoo mobile account. so everytime Jay will send me YM msgs i could receive it via my mobile phone (when im not online). And to reply from mobile to yahoo (Php2.50 also).

So think its worth telling your Filipino Fiancee/GF/wife to use YM Mobile too while she's in the Philippines...