How should Buddhists handle prayer requests? Fairly regularly people ask me to pray for them or their family members. In my understanding, Buddhist don't generally pray for things to be different than what they are. But it never seems appropriate to mention this to a person who might be upset so I just say "of course" and leave it at that. 

But the truth is, outside of metta for everyone, I don't pray for such things as my neighbor's uncle's knee replacement operation or for my co-worker's daughter to advance in the state championship for soccer. So I'm lying to someone and that's uncomfortable and not a good mind state to be in.  

First, is my understanding that Buddhist don't generally pray for things to be other than what they are wrong view? And if not, what might be a better way to handle prayer requests?
This is a great question, certainly understandable. I don't think it's right to say that prayer as an activity goes against the Buddha's teaching; certainly prayer that stems from desire is unwholesome, but prayer that stems from kindness and purity of mind, in the sense of being an expression of one's attitude towards all beings, as:

Sukhino vā khemino hontu sabbe sattā bhavantu sukhitattā &quot;May all beings be happy and secure, with a heart full of happiness!&quot;
(Karaniya Metta Sutta)

is proper, since it leads to tranquility of mind and an outlook based on purity of intention. The problem is only when prayer is based on a sense of need for things to be other than what they are, rather than an outlook that informs one's life (i.e. acting, speaking and thinking for benefit rather than harm)
Another &quot;wrong&quot; regarding prayer, according to Buddhism, would be the localization of the prayer as depending on an external entity (i.e. God). Obviously if by prayer one means the beseeching of an external entity to intervene, that is likely based on both desire and wrong view.
So, in brief, when someone asks you to pray for them or someone else, by all means, say you will if you want; just be clear that to a Buddhist, prayer is simply an expression of &quot;May so and so be happy and well.&quot; That's all anyone wants, is for people to be thinking kindly of them, and it is certainly a means of cultivating harmony and peace, both internally and externally. Just don't succumb to desire for change or expectation of outside intervention.