Known issue: in current version of indico (v1.2) we cannot create Book of Abstracts. We are looking into resolving this issue.
18-21 May 2016
US/Pacific timezone
Several local hotels were called on February 16, 2016. Here is the status:

Budget Inn Redwood City
2526 El Camino Real, Redwood City
15 rooms available
$109 Kings
$99 Queen
Days Inn Palo Alto
4238 El Camino Real, Palo Alto,
5 rooms available
$239 - 10% discount
Listed as well on the website as well at $175/night goverment rate.
Pacific Inn of Redwood City
2610 El Camino Real, Redwood City
10 rooms available
Hotel Lucent
727 El Camino Real, Menlo Park
$439 for Tue-Fri
$159 for Sat-Sun
Web site shows governernment rate ($189) rooms available.
Does not appear on the site.
Red Cottage Inn (quoted 18 Feb 2016)
1704 El Camino Real, Menlo Park
No Gov. rate

For your dates May 17-21 we do have the following discounted rate and room type availability.  

Standard Queen Room                   2 rooms       $ 224.00

Premium King Room                      4 rooms       $ 234.00

Premium Double                            2 rooms       $ 224.00

Redwood Suite - 1 bedroom Suite   1 suite          $ 334.00

Oak Studio                                    1 suite          $ 334.00

Maple Tree Inn
711 E. El Camino Real,  Sunnyvale
This is hotel being used by our competing HEDLA conference. It is rather further from SLAC than the others listed (16 miles, 20-30min drive, but closer than SFO)
On 18 Feb, web site showed availability & prices at $203-208/night.
We may negotiate a reserved block @ $189/room. Stay tuned.

Embassy Suites by Hilton SFO Waterfront
Web site shows "easy cancellation" rooms available at $199+tax/night ($179/night government rate).