"Without a doubt we can pray anywhere, but there is something to be said for having a space that is reserved for prayer. Scripture makes it clear that God doesn't dwell in buildings made by hand any more than God is in the streets or alleys. Still, most of our homes have places where we eat, play, or work. There are also places where God leaves a mark. To be sure, the church is not the building but the people. But it can be nice to have a special place to meet the God we love.
One thing we see in Scripture is that folks like Jacob are commanded to mark the sacred space where God met them, to remember. As we look at spaces like a chapel or a shrine in the Holy Land, we remember not the magic of a physical space but the magic of what God did and who God is; we are reminded that this entire planet is filled with sacred spaces where God meets people.
Consider creating a space where you can get on your knees in the "secret chamber" and be with God. A friend from Brazil started a tradition of tacking prayers on her wall, so she could pray simply by looking at the walls and remembering the needs of her neighborhood and all the prayers God has answered. Some of us keep things that remind us to pray for others, like dog tags of soldiers whose faith has called them to leave the military or a crack valve or a bullet from the streets in our neighborhoods. It is important to remember the things that happen on our streets, both good and bad."
~ Shane Claiborne, Common Prayer: A liturgy for Ordinary Radicals p.159

I've talked to more than one person who have mentioned having a "prayer closet" and until recently I never really thought of creating a particular place in our home where I could go and pray. Honestly, most times if the need for prayer is pressing in and solitude beckons, my location is decided upon the location of my children. If they are upstairs playing in their room, I will sit on our living room floor and light a candle, read some psalms and open my heart to God's presence. I find sitting on the floor the most preferred place where I can still my mind and open my heart to God. That's where I meditate and I find prayer and meditation very close relatives, if not the same sometimes. But certainly my pursuits of prayer are not limited there. Oftentimes I will pray while I do the dishes, when I'm at our kitchen table. I think of my "prayer closet" or place of prayer as being portable.
As of using things to remind me to pray for others, as Claiborne suggests, I never have really implemented that technique before but I definitely find it worthy of incorporating it into my practice. I've talked with others who use rosaries as a way to focus, pictures of loved ones, lists of those who have asked for prayer requests, crosses. Most of the time I just pray and speak to God of whatever comes to my heart unless it is a time where I specifically come before God regarding a request for someone or need. Though I don't use visual reminders I will visualize in my mind the person I am praying for and sometimes the cross, as a way of focusing on God's gift of mercy and love and Jesus' selflessness and compassion.
So, my questions to you are, do you have a specific place in your home that you pray?
and...in your sacred place do you use anything as a visual reminder to help remind you of those you wish to pray for? OR to help center you in prayer?