I heard from somewhere that one can not pray while someone is in front (which is obviously not allowed) , or even if someone is sitting next to you. I often pray while my colleges are sitting next to me on a chair. Is that alright? or do i need to find another spot?
It is perfectly OK to pray when someone is sitting and even lying beside you. The only recommendation that I am aware of is pray in a place where no one can pass in front of you. This does not annuls the prayer as some people might think.
Narrated Aisha (RA)- Sahih Bukhari Passing infront of of someone praying does not break salat, unless it is a dog or donkey.
The things which annul the prayers were mentioned before me. They said, "Prayer is annulled by a dog, a donkey and a woman (if they pass in front of the praying people)." I said, "You have made us (i.e. women) dogs. I saw the Prophet () praying while I used to lie in my bed between him and the Qibla. Whenever I was in need of something, I would slip away. for I disliked to face him."
This hadith from Aisha (RA) says, the prophet used to pray in the room when she would be laying. This is enough to deduce, praying with someone sitting or laying in the room is totally valid. The person who is in the room should respect the person who is praying though. They should not do anything awkward. If they do, you might well want to excuse yourself and pray in separate room.