Pin and others, I've tried those homeopathic remedies, such as the 'New something-or-other' where the tiny pills melt under your tongue, and apart from being annoying having to count them all out, they didn't seem to have any benefit.
If you read my other thread contributions on the subject, nettle tea (with honey) is quite useful, and running in the day (as opposed to evening and morning, because the pollen rises into the sky at these times, so it is high up in the middle of the day).
At the moment, I am taking Benadryl (2-3 times a day) plus a Beclotide preventative inhaler for EIA (exercise induced asthma) and this seems to work, and apart from some wheeziness in the morning (pre-inhale and window open at night!), so don't give up running for the sake of snot!
I find that running alleviates the symptoms somewhat, but comes back when you stop. So, keep running, and you'll feel great!