There has been a Yellow-billed Cuckoo calling for most of the day here 
near the house nearly every day since July 2nd (and once earlier on June 
6th).  It moves around rather continuously.  Every few days, including 
today, there is also the call of a Black-billed Cuckoo.

With the abundance of observations statewide, I thought I'd compare the 
last few years.

Using the data in eBird, the last year with as many Yellow-billed 
Cuckoos was 2007.  In the list below, the first number following each 
year is the number of Vermont locations reporting a Yellow-billed Cuckoo 
for all of that year (for 2011 is the number so far this year).  The 
second number is based on the eBird statistic "total" which is the 
number of birds reported per week, whether from the same location or not 
.... I created the second number by totaling the number of birds 
reported each year through July 15th so it would directly compare with 
this year.

2011   18    22
2010     7      4
2009     4      3
2008     8      8
2007    15   18

So 2007 and 2011 seem to be banner years for Yellow-billed Cuckoos in 
the last five years, with 2009 being the year with the fewest birds and 
least widespread sightings.