Saudi Arabia is quite cheap for using phones. Make sure your phone is unlocked before traveling (check online or flea market or kijiji for unlock).
Mobily offers a temp. sim card which is prepaid, you can also get data on prepaid (unlike Canada) so you can have internet on your phone which is great for getting email, skype, browsing and twitter.
It is also quite affordable to call home (Canada/US) straight from a cell phone in the KSA, approx. .50c a minute to call home! top up codes/cards can be purchased on the street, just make sure when you get your sim, it has data enabled, and perhaps get 100SR ($20 approx.) on purchase of sim.
Getting phone/data on your journey will make things so much easier for you. Internet and wife is virtually non-existent free in the KSA, hotels do not have wifi around the haram and Starbucks etc. do not offer wifi.